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EXPERIMENTAL    RESEARCHES 


APPLIED    TO 


PHYSIOLOGY  AND  PATHOLOGY, 


E.'BROWN-SEQUAfiD, 

M.  D,  OK  THE  FACULTY  OF  PARIS,  LAUREATE  OF  THE  IXSTITUT  DE  FRANCE  ( ACADEMIE 

DES  SCIENCES),   EX-SECRETARY  OF  THE  SOCIETE  PIIILOMATIIIQUE,    AND   OK 

THK  SOCIKTE  DE  BIOLOGIE,  OF  PARIS,  ETC. 


NEW    YORK: 

II.    BAILLIERE,    No.    290    BROADWAY, 
219    REGENT    STREET,    LONDON, 

AND 

RUE  HAUTEFEUILLE,  PARIS. 
1853. 


Entered,  according  to  Act  of  Congress,  in  the  year  of  our  Lord  1853,  by 

II.  BAILLIERE, 

iu  the  Clerk's  Office,  of  the  District  Court,  of  ihe 
Southern  District  of  New  York. 


TABLE  OF  CONTENTS. 


Page. 

I.  On  the  source  of  the  vital  properties,         .  .  .1 

II.  On  the  reflex  faculty,  ....  5 

III.  On  the  influence  of  the  nervous  system  upon  organic  life, .       0 

IV.  On  the  reparative  power  of  the  nervous  system,  .  17 
V.  On  turning  and  rolling  produced  by  injuries  of  the  nervous 

system,        .  .  .  .  .  .18 

VI.  On   a   means  of  measuring   degrees  of  anaesthesia  and 

hyperoesthesia,    .  .  .  .  .23 

VII.  On  the  causes  of  the  torpidity  of  the  tenrec,         .  .25 

VIII.  On  the  influence  of  poisons  upon  animal  heat,  as  a  cause 

of  death,  .....  26 

IX.  Action  of  cold,  warmth  and  light  upon  the  crystalline  lens,     29 
X.  On  the  normal  degree  of  the  temperature  of  man,  .     30 

XI.  Influence  of  the  temperature  of  one  extremity  on  the  tem- 
perature of  the  body,      .  .  .  .  32 

XII.  Coagulability  of  blood,  and  its  circulation  in  frogs,  after 

heart  has  been  cut,  .  .  .  .35 

XIII.  On  a  singular  case  of  animal  graft,     .  .  .30 

XIV.  On  a  convulsive  affection   produced   by  injuries  of  the 

spinal  cord,  .  .  .  .  .36 

XV.  On  the  relations  between  the  organization  of  nerve-tubes 

and  their  vital  properties,  .  .  .  38 

XVI.  On  the  persistence  of  life  in  animals  deprived  of  their 

medulla  oblongata,  .  .  .  .  .40 

XVII.  Influence  of  the  degree  of  animal  heat  on  asphyxia,    .  45 

XVIII.  On  the  central  seat  of  sensibility,  and  on  the  value  of  cries 

as  a  proof  of  pain,  .  .  .  .  .54 

XIX.  On  the  mode  of  action  of  the  most  active  poisons  upon  the 

nervous  system,  .  .  .  .  .57 

XX.  On  the  crossing  of  action  in  the  transmission  of  impres- 
sions in  the  spinal  cord,        .  .  .  .63 


IV  CONTENTS. 

XXI.  On  muscular  irritability  in  paralyzed  limbs,  and  its  semei- 

ological  value,    .  .  .  .  .68 

XXII.  On  the  increase  of  animal   heat,    after   injuries  of  the 

nervous  system,        .  .  .  .  .73 

XXIII.  Cause   of  the   stopping   of    the   heart's   movements,   in 

Weber's  experiment,       .  .  .  .77 

XXIV.  On  a  singular  action  of  air  on  the  gray  matter  of  the 

spinal  cord,  in  birds,  .  .  .  .79 

XXV.  On  the  treatment  of  epilepsy,  .  .  .  80 

XXVI.  Cure  of  epilepsy  by  section  of  a  nerve,     .  .  .84 

XXVII.  Laws  of  the  dynamical  actions  in  man  and  animals,    .  8G 

XXVIII.  Influence  of  red  blood  on  muscles  and  nerves  deprived  of 

their  vital  properties,  .  .  .  .88 

XXIX.  Cases  of  loss  of  sensibility  on  one  side  of  the  body,  and 

loss  of  voluntary  movements  on  the  other  side,     .  95 

XXX.  On  the  different  degrees  of  excitability  of  the  different 

parts  of  the  sensitive  nerve  fibres,       .  .  .98 

XXXI.  The  auditive  nerve  is  a  nervous  centre,  .  .  99 

XXXII.  On    apparently   spontaneous   actions  of    the    contractile 

tissues  of  the  animal  body,    ....  101 
XXXIII.  On  the  cause  of  the  beatings  of  the  heart,       .  .         114 


THE  papers  collected  in  this  book  have  been  published  in  the  Medical 
Examiner,  of  Philadelphia,  from  August,  1852,  to  August,  1853.  They 
form  only  a  part  of  the  author's  original  researches  in  Physiology  and 
Pathology.  A  second  will  soon  be  published,  containing  the  results  of 
the  author's  experiments  and  clinical  observations  on  some  important 
points  of  the  physiology  and  pathology  of  the  different  nervous  centres, 
on  fractures  of  the  spine,  on  the  vital  properties  of  the  iris  and  of  the 
cellular  tissue,  on  the  properties  and  functions  of  the  blood,  on  the  signs 
of  death,  on  electro-physiology,  on  the  laws  of  cadaveric  rigidity  and- 
putrefaction,  and  on  the  etiology  and  treatment  of  some  of  the  nervous 
diseases. 


ERRATA. 


Page  28,  line  31 ;  is  at,  read  is  not  at. 

"      54,    "    15 ;  animation,  read  diminution. 

"      55,  1st  note;  Kay,  read  Fray. 
Pages  58  &  T5,  A.  Barnard,  read  C\  Bernard. 
Page  73,  2d  note;  1853,  read  1852 ;  and  add  or,  ante  Art.  III.,  p.  9. 

"      78,  line  35 ;  molar,  read  motor. 

"       "     "     88 ;  contraction  of  or,  read  contraction  or. 

"    103,    "    13;  after  muscles,  add  of  this  last  limb. 

"[116,     "    16;  to  account,  read  easy  to  account. 

"    117,    "    15  of  the  note ;  any,  read  the. 

tk     "     2d  note ;  Bologne,  read  Biologie. 

"    119,  line  6 ;  Does  that,  read  Why  does. 

"     "      "     26 ;  minutes,  read  times. 

"     "      "     80 ;  any,  read  a. 

"    123,  "     37 ;  so,  read  very. 


EXPERIMENTAL  RESEAKCHES 


APPLIED    TO 


PHYSIOLOGY   AND   PATHOLOGY 


BY 

E.  BROWN-SfiQUARD,  M.  D., 


OF    PARIS/ 


[Reprinted  from  the  Medical  Examiner  for  August,  1852.] 


I. — ON  THE   SOURCE   OF   THE   VITAL   PROPERTIES. 

I  think  that  every  tissue  possesses  its  vital  properties,  in  con- 
sequence of  its  peculiar  organization,  and  that  in  a  completely 
developed  animal,  nutrition  is  the  source  of  the  vital  properties, 
inasmuch  as  it  is  the  cause  of  the  maintenance  of  organization. 

I  will  try  to  prove  the  correctness  of  my  opinion,  by  the  fol- 
lowing remarks  on  some  of  the  vital  properties  of  the  spinal 
cord,  the  nerves,  and  the  muscles. 

[*  The  paper  which  we  have  the  pleasure  of  presenting  to  our  readers 
from  Dr.  Brown-Sequard,  is  a  resume  of  many  researches  made  by  the 
author,  a  part  of  which  only  have  hitherto  been  published  in  any  of  the 
foreign  journals. 

The  conclusions  arrived  at  are  the  result  of  eight  years  exclusive  devotion 
to  the  experiments  upon  which  they  are  based. — EDS.  Ex.] 

1 


a. — Source  of  the  reflex  faculty  in  the  spinal  cord. 

Notwithstanding  the  experiments  of  Redi,  Whytt,  Procbaska, 
Unzer,  Sdnac,  Fontana,  Caldani,  Sir  G.  Blane,  Fray,  Legallois 
and  many  other  experimenters;  and  notwithstanding  the  much 
more  important  experiments  of  Marshall  Hall,  Muller,  Grain- 
ger, Volkmann,  Kurschner,  Pickford,  de  Martino,  Buchner, 
Mayer,  Paton  and  Stilling,  the  existence  of  the  reflex  faculty, 
after  the  spinal  cord  has  been  separated  from  the  encephalon,  is 
not  considered  by  all  physiologists  as  a  proof  of  the  independence 
of  the  spinal  cord.  J.  W.  Arnold  and  Flourens  still  maintain 
that  the  medulla  oblongata  is  a  centre,  giving  life  to  the  other 
parts  of  the  nervous  system.  The  reflex  faculty  possessed  by 
the  spinal  cord  after  it  has  been  separated  from  the  encephalon, 
is  considered  by  J.  W.  Arnold  as  a  remainder  of  something  given 
to  the  spinal  marrow  by  the  encephalon,  before  their  separation. 

My  experiments  prove  the  incorrectness  of  that  opinion.*  I  have 
found  that  after  having  exhausted  the  reflex  faculty  by  putting 
it  in  action,  energetically  and  frequently,  in  an  animal  on  whom 
the  spinal  cord  is  separated  from  the  encephalon,  it  reappears, 
and  becomes  soon  as  energetic  as  before,  provided  that  the  cir- 
culation of  blood  takes  place  in  the  cord.  Moreover  I  have 
found,  that  if  the  reflex  faculty  is  put  in  action  frequently,  it  is 
able  to  produce  an  immense  quantity  of  action :  thus,  for 
instance,  it  can  stimulate  sufficiently  the  muscles  of  a  frog's  leg 
to  make  them  raise,  in  an  hour  and  in  divided  portions,  about  twelve 
pounds,  to  the  height  of  about  two  lines.  In  a  pigeon  the  reflex 
faculty  is  able  to  stimulate  the  muscles  of  a  leg  so  far  as  to  make 
them  raise  fifty  pounds,  by  fractions,  in  an  hour,  to  the  height 
of  more  than  one  inch.f 

I  shall  add  two  other  decisive  proofs  : — 1.  The  reflex  faculty 
is  very  weak  in  frogs  immediately  after  the  spinal  cord  has  been 
separated  from  the  medulla  oblongata,  and  it  increases  after- 
wards, as  R.  Whytt  and  Marshall  Hall  have  discovered.  I  have 
stated  that  it  increases  so  much  that  the  posterior  limbs  are  able 

*  See  : — Recherches  et  experiences  sur  la  physiologie  de  la  moelle  epi- 
mere.  These  inaugurate.  Paris,  3  Janvier,  1846. — Comptes  rendus  des 
seances  de  1' Academic  des  Sciences.  Paris,  1847  T.  xxiv.  p.  849. 

tSee  Gaz.  Med.  de  Paris.     T.  4.     1849.     p.  233. 


to  draw  up,  by  reflex  action,  more  than  double  the  weight 
the  animal  could  raise  up  by  an  action  of  its  will  before  the 
division  of  the  cord.  2.  After  having  divided  the  spinal  cord  in 
the  dorsal  region  on  a  mammal,  I  kill  it  by  cutting  the  right 
carotid  artery.  A  few  minutes  after  the  cessation  of  reflex 
action  I  inject  blood  by  the  opening  made  in  the  carotid.  Then 
life  returns  and  with  it  the  reflex  faculty. 

All  these  facts  demonstrate  positively  that  the  reflex  faculty 
is  a  vital  property  belonging  to  the  spinal  cord,  and  that  its 
source  is  in  the  nutrition  which  maintains  the  organization  of  that 
nervous  centre. 

b. — Source  of  the  vital  property  of  the  motor  nerves. 

The  independence  of  the  motor  nerves  is  denied  by  almost  all 
physiologists.  They  believe  that  the  nervous  centres  are  the 
sources  of  the  vital  property  of  these  nerves.  They  base  their 
opinion  on  this  fact,  that  the  motor  nerves  separated  from  the 
nervous  centres  soon  lose  their  property,  as  it  has  been  seen  by 
Fontana,  Haighton,  Astley  Cooper,  Steinrueck,  Mu'ller,  Sticker, 
Giinther,  Schoen,  Kilian,  Stannius,  Helmholtz,  Martin-Magron 
and  others. 

But,  in  the  first  place,  if  the  motor  nerves  of  the  warm-blooded 
animals  lose  their  vital  property  after  having  been  separated 
from  the  nervous  centres,  it  is  not  less  positive  that  they  retain 
it  during  several  days.  Secondly,  if  the  vital  property  of  the 
motor  nerves  is  exhausted  by  very  energetic  action,  it  re- 
appears after  a  short  time,  although  the  nerves  are  separated 
from  the  cerebro-rachidian  centre,  provided  that  the  circula- 
tion of  blood  continues  in  them.  Thirdly,  if  the  circulation 
of  blood  is  stopped  in  a  limb  in  which  the  nerves  have  been 
divided,  it  is  found  that  the  peripheric  portion  of  the  divided 
nerves  lose  their  vital  property  before  the  muscles.  After  the 
nerves  have  been  left  dead,  i.  e.,  deprived  of  their  vital  property 
for  a  quarter  of  an  hour,  half  an  hour,  and  even  more,  blood  is 
allowed  to  circulate  anew  in  the  limb.  Then  the  vital  property 
of  the  cut  nerves  returns,  and,  to  produce  a  muscular  contrac- 
tion, only  a  slight  compression  upon  them  is  necessary.*  If  the 

*See  Comptes  rendus  de  1'Aead.  des  Sciences.  T.  xxxii.  Seance  du  9 
Juin,  1851. — Gaz.  Medic,  de  Paris.  1851.  T.  vi,  p.  359. 


motor  nerves  lose  their  property  when  they  are  separated  from 
the  nervous  centres,  it  is  because  they  are  then  badly  nourished. 
Nerves  as  well  as  muscles  must  be  exercised,  in  order  to  be 
well  nourished. 

c. — Source  of  the  muscular  contractility. 

Although  there  are  some  facts  which  appear  strongly  to  prove 
that  the  vital  property  of  the  muscular  tissue  is  independent  of 
the  nervous  system,  many  physiologists  persist  in  their  opposi- 
tion to  Haller's  doctrine  on  this  subject.  Therefore  I  have 
thought  necessary  to  add  new  proofs  to  those  already  known, 
and  I  have  published  many  experiments,  of  which  I  shall  relate 
here  only  two  of  the  most  decisive.* 

1.  The  sciatic  and  the  crural  nerves  having  been  resected,  for 
ten  or  twelve  days,  on  a  rabbit  or  a  guinea-pig,  I  examine  if  these 
nerves  have    completely  lost  their  vital  property,  and  if  the 
muscles  are  still  contractile.     When  this  has  been  ascertained,  I 
put  a  ligature  around  the  aorta.     Then  muscular  irritability  dis- 
appears after  a  certain  time  and  cadaveric  rigidity  appears. 
Three  quarters  of  an  hour  or  even   an  hour  after  the  complete 
disappearance  of  the  muscular  irritability,  and  the  appearance  of 
the  rigor  mortis,  I  cut  off  the  ligature,  and  I  find,  after  ten  or  fif- 
teen minutes,  that  the  rigidity  disappears  and  the  contractility 
reappears.     I  need  not  say  that  the  nerves  do  not  regain  their 
lost  property.     This  fact  clearly  proves  that  the  contractility  is 
given  to  the  muscles  by  blood,  i.  e.,  by  nutrition,  and  not  by  the 
nervous  system. 

2.  Many  experiments  have  shown  to  me  that  muscles  paralyzed 
for  five  days  or  a  little  more,  in  consequence  of  the  division  of 
their  nerves,  remain  much  longer  contractile  after  the  death  of  the 
animal  than  the  non-palsied  muscles.     This  would  hardly  be  the 
case  if  the  contractility  was  given  to  muscles  by  the  nervous 
system. 

*  See:— Bulletin  de  la  Soc.  Philomat.  1847,  p.  74.— Gaz.  Med.  de   Paris, 
1851,  t.  vi.  p.  619,  and  1852,  t.  vii.  p.  72. 


II. — RESEARCHES  ON  THE  REFLEX  FACULTY. 

During  the  last  seven  years  I  have  published  many  papers  re- 
lating to  the  reflex  faculty.*  Among  the  facts  which  I  have 
discovered  I  will  mention  the  following : 

1.  Grainger  had  found  that  the  act  of  suckling  can  be  exe- 
cuted by  an  animal  deprived   of  its   brain.     I  have  found  that 
even  after  the  ablation   of  both  the  brain  and  the  cerebellum, 
newly-born   rabbits  are  able  to   suckle  very  well;  which  is   a 
proof  that  suckling  may  be  executed  by  reflex  action. 

2.  It  is  commonly  affirmed   that  the  reflex  power  is  much 
stronger  in   cold-blooded  than  in  warm-blooded  animals.     This 
opinion  is  correct  so  far  as  regards  the  contrast  between  Mam- 
mals and  Batrachia   (the   animals  usually  compared) ;  but  it  is 
incorrect  if  Birds  are  compared  with  Reptilia  and  Fishes.  It  has 
been  said  that  the  higher  an  animal  is  in  the  scale  the  less  it 
has  reflex  power.     If  this  be  true,  we  should  find  more  and  more 
reflex  power  from  Mammals  to  Fishes ;  but  the  real  order,  ac- 
cording to  my  experience  is  :  1st,  Fishes;  2d,  Mammals;  3d,  Am- 
phibia  and  Reptilia  ;  4th,  Birds ;   so  that  Birds  have  more  reflex 
power  than  all  the  other  animals,  and  Mammals  have  more  than 
Fishes.     Of  course,  there  are  exceptions  to  this  rule  in  the  case 
of  particular   species ;    thus   the  eel,   carp    and   tench  have  as 
much  reflex  power  as  many  Mammals  possess. 

It  has  also  been  commonly  affirmed  that  the  reflex  power 
diminishes  with  age,  being  the  greatest  in  young  animals.  This 
statement,  also,  has  been  based  on  a  too  limited  induction.  In 
Reptiles  and  Fishes  no  difference  can  be  detected  in  this  parti- 
cular. In  Birds  it  is  decidedly  the  other  way,  the  reflex  power 
being  much  the  strongest  in  adults.  Among  Mammals  the  dif- 
ference is  usually  in  favor  of  the  young  animal ;  not,  however, 
at  the  very  earliest  part  of  its  life,  but  ten  or  twelve  days  after 
birth.  As  to  man  the  reflex  power  appears  to  be  greater  in  him 
than  in  Fishes  and  Mammals ;  but  it  is  not  so  energetic  as  in 
Birds  and  in  Amphibia. 

I  have  found  that  the  causes  of  the  differences  between  differ- 

*  See  rny  Inaugural  Dissertation,  Paris,  3  Janvier  1846,  lere  partie. — 
Comptes  rendus  de  1'Acad.  des  Sciences,  1847,  t.  xxiv.  pp.  363  et  859. — Gaz. 
Med.  de  Paris,  1849,  t.  iv.  pp.  430  et  644  ;  et  1850  t.  v.  pp,  98  et  476. 

1* 


6 

ent  animals,  as  regards  the  energy  of  their  reflex  power,  are 
to  be  explained  by  anatomical  differences.  There  exists  a  con- 
stant relation  between  the  degree  of  the  reflex  power  and  the 
amount  of  grey  matter  in  the  spinal  cord.  It  appears,  also, 
that  the  mode  of  circulation  of  the  blood  in  the  spinal  marrow 
has  a  great  share  in  the  causes  of  differences  amongst  different 
animals. 

3.  It  is  not  necessary  for  the  existence  of  the  reflex  power 
that  the  spinal  cord  should  be  without  alteration.     I  have  found 
the  reflex  faculty  remaining  in  pigeons  after  I  had  crushed  the 
spinal  cord,  and  produced  in  it  a  considerable  alteration.     This 
is   important  to  be   known   by  practitioners,  to   prevent  their 
drawing  the  conclusion,  from  the  existence  of  reflex  action  after 
a  fracture  or  a  luxation  of  the  vertebral  column  in  man,  that  the 
spinal  cord  is  healthy. 

4.  The  influence  of  the  nervous  system  on  the  secretions,  by 
a  reflex  action,  has  been  very  little  studied.     I  will  state  two 
examples  of  these  reflex  secretions :  1st,  There  is  on  the  face, 
and  particularly  on  the  forehead  and  the  nose,  an  abundant  pro- 
duction of  sweat  when   the  nerves  of  the  taste    are   strongly 
excited,  as  they  are,  for  instance,  by  common  salt,  pepper,  sugar, 
etc.     In  certain  persons  the  quantity  of  sweat  produced  in  such 
cases  is  sometimes,  even  in  the  winter,  very  considerable.     2d, 
I  have  observed  that  it  is  sufficient  to  excite  the  nerves  of  taste 
in  order  to  produce  the  secretion  of  gastric  juice,  bile  and  pan- 
creatic juice. 

Ill RESEARCHES  ON  THE   INFLUENCE    OF   THE   NERVOUS  SYSTEM 

UPON  THE   FUNCTIONS   OF   ORGANIC  LIFE. 

My  experiments  have  convinced  me  that  if  it  is  certain  that 
the  nervous  system  is  able  to  act,  and  frequently  does  act,  on  the 
functions  of  organic  life,  it  is  not  the  less  certain  that  the  action 
of  the  nervous  system  on  these  functions  is  not  necessary.  I 
hope  this  will  be  sufficiently  demonstrated  by  the  numerous  facts 
I  have  to  relate. 

a.  Influence  of  the  section  of  nerves  on  nutrition  and  secretion. 

1.  The  frequent  occurrence  of  certain  pathological  changes 
after  section  of  the  sciatic  nerve  in  Mammals,  has  been  cited  as 


a  proof  of  the  dependence  of  the  nutritive  operations  upon 
nervous  agency.  I  think  the  following  experiments  give  evi- 
dence against  that  doctrine.  I  have  divided  the  sciatic  nerve 
in  a  number  of  rabbits  and  guinea-pigs,  and  placed  some  of  them 
at  liberty  in  a  room  with  a  paved  floor,  whilst  I  confined  others 
in  a  box,  the  bottom  of  which  was  thickly  covered  with  bran,  hay 
and  old  clothes.  In  a  fortnight,  the  former  set  exhibited  an  ob- 
viously disordered  action  in  the  paralysed  limbs ;  the  claws  were 
entirely  lost ;  the  extremities  of  the  feet  were  swollen,  and  the 
exposed  tissues  were  red,  engorged,  and  covered  with  fleshy  gra- 
nulations. At  the  end  of  a  month,  these  alterations  were  more 
decided,  and  necrosis  had  supervened  in  the  denuded  bones.  On 
the  other  hand  in  the  animals  confined  in  the  boxes,  no  such 
injuries  had  accrued  ;  and  although  some  of  them  have  been 
kept  living  for  four,  five  and  even  six  months  after  the  division 
of  the  sciatic  nerve,  no  alteration  whatever  has  appeared  in  the 
palsied  limbs  except  atrophy.  In  these  cases  a  portion  of  the 
nerve  had  been  cut  off,  so  that  reunion  was  nearly  impossible 
and  did  not  take  place. 

Experiments  made  on  pigeons  have  given  the  same  results. 

It  is  obvious  from  these  experiments  that  the  pathological 
changes  which  occur  after  the  section  of  the  sciatic  nerve  do  not 
proceed  directly  from  the  absence  of  nervous  action,  but  that 
they  are  consequent  upon  the  friction  and  continual  compression 
to  which  the  paralysed  limbs  are  subject,  against  a  hard  soil, 
owing  to  the  inability  of  the  animal  to  feel  or  avoid  it. 

In  similar  experiments  made  on  frogs,  I  found  that  no  altera- 
tion took  place,  except  when  water  penetrated  through  the 
wound,  under  the  skin,  and  between  the  muscles.* 

2.  With  the  help  of  an  eminent  micrographer  (Dr.  Lebert),  I 
have  made  researches  on  the  influences  produced  on  the  capillary 
circulation  in  consequence  of  the  section  of  all  the  nerves  (sym- 
pathetic and  cerebro-spinal  nerves)  in  the  legs  of  a  number  of 
frogs.     We  have  found  no  appearance  of  trouble  in  the  capillary 
circulation,  neither  in  an  hour,  nor  in  three  or  four  days  after  the 
division  of  the  nerves. 

3.  When  resection  of  a  long  portion   of  one  of  the  sciatic 
and  the  crural  nerves  is  made  on  a  very  young  rabbit,  guinea- 

*  See  Gaz.  Med.  de  Paris.  1849;  t.  4,  p.  880. 


8 

pig  or  pigeon,  the  palsied  limb  continues  to  grow  in  length,  but 
it  grows  only  very  little,  if  at  all,  in  thickness.  When  the 
experiment  is  made  on  all  the  nerves  of  the  wing  in  a  very 
young  pigeon,  it  is  also  found  that  the  wing  grows  in  length,  but 
very  little  in  breadth  or  in  thickness.  The  secretion  of  quills 
takes  place  equally  as  well  in  the  palsied  limb  as  in  the  other. 

The  diiference  in  all  these  cases  between  the  length  of  the 
sound  and  that  of  the  palsied  limb  or  wing  is  never  very  consi- 
derable ;  nevertheless  the  length  of  the  healthy  parts  is  greater 
than  that  of  the  paralysed  parts. 

4.  I  have  found  that  burns,  wounds  and  ulcerations  existing 
in  parts  palsied  in  consequence  of  the  section  of  their  cerebro- 
spinal  nerves,  are  cured  as  quickly  and  as  well  as  those  in  sound 
parts. 

5.  Atrophy  is  a  constant  consequence  of  the  section  of  the 
nerves  of  a  limb.     I  have  found  that  it  supervenes  not  only  in 
the  muscles  and  the  bones,  as  J.  Reid  has  discovered,  but  also  in 
the  skin,  which  becomes  evidently  thinner. 

6.  Krimer  asserts  that  after  the  section   of  the  nerves  of  a 
limb  in  Mammals,  the  venous  blood  is  of  a  bright  red  color  like 
the   arterial  blood.    (Physiologische  Untersuchungen,  Leipzig, 
1820,  p.  138  exp.  1,  and  p.  152  exp.  9.) 

Long  before  the  publication  of  Krimer,  Arnemann  had  de- 
clared that  the  blood  appeared  darker  than  usual  in  a  limb  on 
which  all  the  nerves  had  been  cut.  (Versuche  iiber  die  Regera- 
tion  an  lebenden  thieren,  Gottingen,  1786,  t.  i.,  p.  48.) 

Longet  (Traitd  de  Physiologic,  Paris,  1850,  t.  ii.,  B.  p.  92,) 
says  that  he  has  seen  the  venous  blood  retaining  its  ordinary 
color  even  three  days  after  the  section  of  the  nerves  of  the 
anterior  limb  in  dogs. 

Who  is  right — Krimer,  Arnemann  or  Longet  ?  Neither  of 
them  is  perfectly  right.  The  assertion  of  Arnemann  is  entirely 
incorrect.  By  experiments  made  on  dogs,  rabbits,  guinea- 
pigs  and  pigeons,  I  have  found  that  the  venous  blood  in  palsied 
limbs  is  evidently  less  black  than  it  is  in  sound  limbs.  But  it  is 
not  true  to  say  that  venous  and  arterial  blood  in  paralysed  limbs 
have  the  same  color.  It  is  always  very  easy  to  distinguish  one 
from  the  other. 

The  transformation  of  the  arterial  blood  into  venous  is  not  so 


9 

complete  in  the  palsied  as  in  the  sound  limb,  but  it  always  takes 
place  even  in  a  great  measure.  There  is  a  good  proof  of  this 
in  the  result  of  my  experiments  on  the  hand  and  forearms  of 
two  decapitated  men.  I  injected  blood  in  the  arteries  of  .these 
parts  thirteen  or  fourteen  hours  after  death  and  when  cadaveric 
rigidity  existed.  Surely  there  was  in  that  case  no  nervous 
action  whatever,  and  nevertheless  the  blood,  which  was  of  a 
bright  red  color  when  injected,  came  out  nearly  black  from  the 
veins  ! 

From  all  these  facts  I  shall  conclude : 

1st,  That  the  nervous  action  (that  of  the  sympathetic  as  well 
as  that  of  the  cerebro-spinal  nerves)  is  not  necessary  for  the 
change  of  color  of  the  blood  in  the  capillaries. 

2d,  That  the  nervous  system  of  animal  life  has  an  influence 
upon  nutrition  by  which  it  takes  a  share  in  the  transformation 
of  arterial  into  venous  blood. 

7.  My  friend  Dr.  Cl.  Bernard  has  recently  discovered  the 
curious  fact,  that  after  the  section  of  the  sympathetic  nerve  in 
the  neck,  the  face  on  the  same  side  and  more  particularly  the 
ear,  become  warmer  and  more  sensible  than  the  other  side.  The 
blood-vessels  are  much  enlarged  and  a  great  many  are  visible 
which  were  not  so  before  the  operation. 

I  have  found  that  the  remarkable  phenomena  which  follow 
the  section  of  the  cervical  part  of  the  sympathetic,  are  mere  con- 
sequences of  the  paralysis  and  therefore  of  the  dilatation  of  the 
bloodvessels.  The  blood  finding  a  larger  way  than  usual,  arrives 
there  in  greater  quantity  ;  therefore  the  nutrition  is  more  active. 
Now  the  sensibility  is  increased  because  the  vital  properties  of 
the  nerves  are  augmented  when  their  nutrition  is  augmented. 
As  to  the  elevation  of  the  temperature,  I  have  seen,  as  Dr.  Ber- 
nard has,  that  the  ear  exhibits,  sometimes,  one  or  two  degrees  Fahr. 
more  than  the  rectum ;  but  it  must  be  remarked  that  the  tem- 
perature of  the  rectum  is  a  little  lower  than  that  of  the  blood ; 
and  as  the  ear  is  full  of  blood,  it  is  very  easy  to  understand  why 
it  has  the  temperature  of  the  blood.  A  great  many  facts  prove 
that  the  degree  of  temperature  and  of  sensibility  of  a  part,  is  in 
close  relation  with  the  quantity  of  blood  circulating  in  that  part. 

I  base  my  opinion  in  part  on  the  following  experiments  :  If 
galvanism  is  applied  to  the  superior  portion  of  the  sympathetic 


10 

after  it  lias  been  cut  in  the  neck,  the  vessels  of  the  face  and  of 
the  ear  after  a  certain  time  begin  to  contract ;  their  contraction 
increases  slowly,  but  at  last  it  is  evident  that  they  resume  their 
normal  condition,  if  they  are  not  even  smaller.  Then  the  tem- 
perature and  the  sensibility  diminish  in  the  face  and  the  ear,  and 
they  become  in  the  palsied  side  the  same  as  in  the  sound  side. 

When  the  galvanic  current  ceases  to  act,  the  vessels  begin  to 
dilate  again,  and  all  the  phenomena  discovered  by  Dr.  Bernard 
reappear. 

I  conclude,  that  the  only  direct  effect  of  the  section  of  the 
cervical  part  of  the  sympathetic,  is  the  paralysis  and  conse- 
quently the  dilatation  of  the  bloodvessels.  Another  evident  con- 
clusion is,  that  the  cervical  sympathetic  send  motor  nerve  fibres 
to  many  of  the  bloodvessels  of  the  head.* 

8.  Nearly  all  physiologists  believe  that  the  secretion  of  the 
gastric  juice  is  stopped  after  the  section  of  the  two  pneumo- 
gastric  nerves.  It  is  difficult  to  solve  the  question  by  experi- 
ments on  warm-blooded  animals,  because  they  die  too  quickly  after 
the  section  of  the  vagi.  But  it  is  not  so  with  frogs.  I  have 
found  that  they  are  able  to  live  perfectly  well  either  after  the 
extirpation  of  the  medulla  oblongata,  or  after  the  extirpation  of 
the  ganglia  of  the  par  vagum.  In  both  these  cases  I  have  found 
that  digestion  continues  to  be  performed.  Consequently,  if  the 
gastric  juice  is  necessary  to  digestion,  it  is  certain  that  this 
liquid  is  secreted.f 

*  My  experiments  prove,  also,  that  the  bloodvessels  are  contractile,  and 
that  the  nerves  are  able  to  put  them  in  action.  I  have  also  to  remark  that 
it  is  a  fact,  well  established  by  Budge  and  Waller,  that  the  cervical  sympa- 
thetic is  one  of  the  motor  nerves  of  the  iris,  and  that  the  spinal  cord  is  the 
origin  of  the  nerve-fibres  going  from  the  sympathetic  to  the  iris.  Some 
experiments,  which  I  intend  to  perform  again,  appear  to  prove  that  the 
same  parts  of  the  spinal  cord  which  give  origin  to  some  of  the  motor  nerve- 
fibres  of  the  iris,  originate  also  the  motor  nerve-fibres  going  from  the  cer- 
vical sympathetic  to  the  vessels  of  the  head.  Another  conclusion  is  to  be 
drawn  from  the  results  obtained  by  Budge,  Waller,  Bernard  and  myself;  it 
is  that  the  cervical  sympathetic,  instead  of  receiving  its  fibres  from  upwards 
to  give  them  downwards,  received  them  downwards  and  distributes  them 
upwards. 

~j~Comptes  rendus  de  1'Acad.  des  Sciences.  Paris,  1847.  T.  xxiv.  p. 
363-64. 


11 

9.  J.  Reid  has  found,  that  if  the  four  nerves  uniting  the  spinal 
cord  to  the  posterior  limbs  are  cut  across  on  both  sides,  in 
frogs,  and  if  a  galvanic  current  is  applied  every  day  to  the  pal- 
sied limbs  on  one  side,  these  galvanized  limbs  retain  their  natural 
dimensions,  while  the  palsied  limbs  not  galvanised  become 
atrophied. 

I  have  found  : — 1.  That  if,  instead  of  cutting  only  the  four 
cerebro-spinal  nerves  of  the  posterior  limbs,  I  divide  also  the 
branches  of  the  sympathetic  nerve  which  unite  with  them,  the 
same  results  are  obtained  as  in  Reid's  experiment.  2.  That  if  a 
like  experiment  is  performed  on  dogs,  guinea-pigs,  rabbits  and 
pigeons,  the  same  results  are  found.  3.  That  if  after  atrophy 
has  taken  place  in  the  limb  of  a  mammal  or  a  pigeon,  a  galvanic 
current  is  applied,  every  day,  during  several  weeks,  the  atrophy 
diminishes  little  by  little  and  the  limb  at  length  becomes  as  large 
as  a  sound  limb.  This  happens  although  there  is  no  return  of 
vital  property  in  the  divided  nerves.  4.  That  if  the  application 
of  galvanism  is  made  on  the  palsied  limbs  of  very  young  animals, 
and  continued  every  day  until  they  have  arrived  at  adult  age, 
these  limbs  are  then  found  to  have  grown  as  much,  in  every  re- 
spect, as  the  sound  limbs. 

In  addition  to  these  facts  I  have  to  state  that  in  cases  of  lead 
palsy,  in  which  the  extensor  muscles,  as  far  as  I  have  been  able 
to  judge,  were  completely  destroyed  and  replaced  by  fibrous 
tissue,  I  have  seen  muscles  created  by  galvanism  and  becoming 
as  strong  as  they  are  in  healthy  men. 

In  a  case,  which  I  published  two  years  ago,  (Gaz.  Med. 
de  Paris,  1850,  t.  v.  p.  169,)  I  have  found  that  an  increase 
of  five  centimetres  in  circumference  took  place  in  the  superior 
part  of  the  leg  of  a  young  gentleman,  under  the  influence  of  gal- 
vanism, applied  three  quarters  of  an  hour  each  day  for  six  days. 
In  all  the  facts  before  related,  galvanism  acts  by  two  ways  : 
the  one  is  that  it  exercises  the  muscles,  and  increase  in  conse- 
quence their  nutrition ;  the  other  is  that  it  produces  directly 
some  of  the  chemical  changes  which  constitute  nutrition. 

The  atrophy,  which  happens  in  paralyzed  muscles,  takes  place 
mostly  because  they  remain  without  exercise,  and  partly  because 
when  nervous  action  is  deficient  the  respiration  of  the  muscles  is 
not  carried  on  as  well  as  when  the  nervous  system  acts  upon 


12 

them.  Galvanism  applied  to  a  palsied  limb  acts  partly  in  pro- 
ducing the  transformation  of  arterial  into  venous  blood,  i.  e., 
what  Gustav  Liebig  calls  the  respiration  of  the  muscles.  I  have 
seen  frequently  the  venous  blood,  in  palsied  limbs,  becoming  as 
black  as  normal  venous  blood,  after  the  application  of  galvanism. 
This  change  of  coloration  is  not  produced  by  a  direct  chemical 
influence,  exerted  by  galvanism  on  the  blood,  for  if  galvanism  is 
applied  to  blood  in  a  vase,  nothing  of  that  kind  is  seen.  It  is  in 
consequence  of  an  interchange  between  blood  and  the  living 
tissues  that  the  change  of  color  happens.  The  muscular  con- 
traction which  takes  place  under  the  influence  of  the  nervous 
system,  or  that  of  galvanism,  produces,  in  both  cases,  an  increase 
in  the  darkness  of  the  venous  blood.  This  fact  proves  that  the 
consumption  of  oxygen  by  muscles  is  increased  during  their 
contraction. 

I  conclude  from  the  preceding  facts  : — 

1st.  Nervous  action  is  not  necessary  for  nutrition. 

2d.  Atrophy  in  palsied  limbs  is  more  a  consequence  of  absence 
of  exercise  than  of  any  other  cause. 

3d.  Muscular  atrophy,  at  any  stage,  may  be  cured  by 
galvanism. 

b. — Influence  of  the  nervous  centres  on  nutrition  and  secretion. 

1.  Every  one  knows  the  singular  alterations  which  take  place 
in  the  eye  after  a  contusion  of  the  frontal  nerve,  or  a  section  of 
the  trigeminal  or  the  cervical  sympathetic  nerves.  Every  one 
knows  also  that  the  existence  of  worms  in  the  intestinal  canal, 
and  also  certain  affections  of  the  spinal  cord,  are  able  to  produce 
morbid  phenomena  in  vision,  and  even  diseases  of  the  eye, 
and  especially  amaurosis.  I  have  found  that  after  the  section 
of  a  lateral  half  of  the  spinal  cord,  it  sometimes  happens  that  the 
eye,  on  the  same  side  where  the  cord  has  been  wounded,  will 
present  strange  and  various  alterations.  The  part  of  the  cord 
having  that  influence  on  the  eye,  lies  between  the  ninth  and  the 
twelfth  costal  vertebrae.  The  alteration  exists  generally  in  the 
cornea.  In  one  case  a  ridge  appeared  on  the  anterior  surface 
of  that  membrane  four  days  after  the  operation.  On  the  fifth 
day  the  ridge  was  deeper,  and  its  edges  had  become  opaque ;  on 
the  sixth  day  all  the  cornea  was  opaque.  It  remained  so  for 


13 

five  days,  after  which  the  opacity  disappeared  and  no  trace  re- 
mained of  it,  or  of  the  ridge.  This  experiment  has  been  made 
on  guinea-pigs. 

2.  I  have  found  a  considerable  hypertrophy  of  the  two  supra- 
renal capsules,  on  eight  or  ten  guinea-pigs,  upon  which  a  lateral 
half  of  the  spinal  cord  had  been  cut  in  the   dorsal  region,  for 
eight,  ten   or  fifteen  months.     These  organs  had  acquired,  in 
some  of  these  cases,  three  times  their  natural  dimensions,  and  in 
others  only  the  double.     There  was  no  appearance  of  change  in 
their  structure. 

By  an  examination  of  the  supra-renal  capsules  in  guinea-pigs, 
on  which  I  had  made  the  section  of  a  lateral  half  of  the  spinal 
cord,  a  few  hours  or  a  few  days  previously,  I  have  found  these 
organs  congested,  and  sometimes  containing  even  a  slight  effu- 
sion of  blood.  It  is  very  probable  that  such  a  congestion  has 
been  the  cause  of  the  hypertrophy  found  in  animals  operated  on 
at  a  much  longer  time  previously.  The  congestion  is  certainly 
the  result  of  a  peculiar  disturbance  in  the  nervous  action.  A 
part  only  of  the  spinal  cord  appears  to  possess  that  singular 
influence  on  the  supra-renal  capsules.  That  part  is  extended, 
in  guinea-pigs,  from  the  tenth  costal  vertebra  to  the  third  lumbar. 

A  simple  puncture  of  the  cord  is  frequently  sufficient  to  pro- 
duce the  congestion  of  both  supra-renal  capsules. 

3.  The  researches,  made  before  mine,  as  to  the  influence  of 
the  spinal  cord  on  the  urinary  secretion,  could  not  give  a  decided 
result,  because  no  physiologist  had  been  able  to  keep  any  warm- 
blooded animal  living  a  sufficient  time,  after  the  destruction  of  a 
large  part  of  the  spinal  cord. 

The  results  obtained  by  S^galas  on  seme  animals  who  have 
lived  from  fifteen  minutes  to  an  hour  after  the  destruction  of  the 
lumbar  part  of  the  cord,  had  led  him  to  conclude  that  the  spinal 
cord  has  no  influence  on  the  urinary  secretion.  Longet  (Trait£ 
de  Physiologic,  Paris,  1850,  t.  ii.  B.  p.  199)  says  : — "  Many  ob- 
servations have  demonstrated  to  me  that  the  visceral  organs, 
which  receive  their  nerves  from  the  sympathetic,  are  far  from 
being  immediately  paralyzed  by  the  section  of  these  nerves,  and 
that  their  action  is  even  maintained  much  longer  than  the  dura- 
tion of  the  experiments  in  which  Segalas  had  destroyed  the  spinal 

n 


14 

marrow.*  Therefore  I  think  I  am  allowed  to  maintain  that  after 
such  an  injury,  the  nerves  going  to  these  organs,  and  more  par- 
ticularly to  the  kidneys,  do  nothing  but  spend  little  by  little 
the  nervous  force,  originally  and  principally  derived  from  the 
spinal  marrow,  which  is  the  chief,  if  not  the  exclusive  centre  of 
its  production  ;  thence  the  persistence  of  the  renal  secretion,  as 
well  as  that  of  the  movements  of  the  heart,  the  intestinal  canal, 
the  uterine  cornua,  etc." 

I  could  relate  a  great  many  experiments  proving  the  incorrect- 
ness of  Longet's  theory,  but  a  single  one  is  sufficient.  I  have  kept 
living,  nearly  three  months,  a  young  cat,  on  which  the  spinal 
cord  had  been  completely  destroyed  from  the  eleventh  or  twelfth 
costal  vertebra  to  its  termination.  This  cat  has  lived  all  that 
time  in  apparently  good  health,  and  its  urine  has  always  been 
perfectly  normal.  It  was  acid,  as  is  the  case  constantly  in  cats 
fed  on  meat,  milk  and  bread.  The  bladder  was  palsied,  but  the 
sphincter  vesicae  was  generally  contracted,  so  that  every  day  I 
had  to  compress  the  abdomen  and  the  bladder  to  empty  this 
pouch.  When  I  remained  two  days  without  doing  that  ope- 
ration, the  bladder  contracted  in  consequence  of  the  excitation 
produced  on  its  muscular  fibres  by  their  distension. 

This  fact  clearly  proves  that  the  urinary  secretion  is  not  under 
the  dependence  of  the  spinal  cord. 

According  to  Krimer,  the  medulla  oblongata  is  the  nervous 
centre  upon  which  the  urinary  secretion  depends.  My  experi- 
ments prove  that  this  opinion  is  incorrect : — 1st.  After  the  destruc- 
tion of  the  medulla  oblongata  in  frogs,  I  have  found  that  the 
secretion  of  urine  remains  as  long  as  the  animals  have  lived,  i.  e., 
three  or  four  months.  2d.  On  hybernating  mammals,  in  winter 
time  I  have  extirpated  the  medulla  oblongata,  after  having 
emptied  the  bladder.  These  animals  have  lived  a  little  more 
than  a  day,  when  I  took  the  precaution  of  insufflating  air  in  their 
lungs  many  times  each  hour.  After  their  death  the  bladder  was 
found  full  of  urine  apparently  normal. 

The  medulla  oblongata  is  not  therefore  a  centre  on  which  the 
•urinary  secretion  depends. 

4.  The  well  known  opinions   of  Segalas,  W.  Philip,  Krimer, 

*  The  italics  are  Longet's. 


15 

Chossat,  Longet  and  others,  about  the  influence  of  the  spinal 
cord  on  the  functions  of  organic  life,  are  quite  erroneous.  I  have 
found  that  birds  are  able  to  live  for  months  after  the  destruction 
of  the  spinal  cord,  from  the  fifth  costal  vertebra  to  its  termina- 
tion. This  fact  proves  not  only  that  the  functions  of  organic 
life  may  continue  to  exist  in  such  a  case,  but  that  they  appear  to 
be  executed  then  as  in  healthy  birds  ;  for,  if  the  operation  has 
been  made  on  a  young  bird,  it  will  afterwards  grow  very  well. 

I  have  succeeded  in  keeping  alive,  from  the  8th  of  April  until 
the  4th  of  July,  a  young  cat,  about  which  I  have  already  pub- 
lished a  note  in  this  journal.*  The  palsied  parts  in  this  animal 
have  grown  in  length  proportionately  as  much  as  the  sound  parts. 
The  growth  has  been  such  in  the  palsied  limbs  that  they  have  ac- 
quired more  than  double  the  length  they  had  at  the  time 
of  the  operation.  The  functions  of  organic  life  appeared  to 
exist  without  any  apparent  disturbance.  The  nutritive  reparation 
was  so  powerful,  that  the  pieces  of  the  vertebral  column  which 
had  been  cut  off  have  been  reproduced.  This  fact  is  important, 
because  it  shows  that  the  reproduction  of  bone  is  possible  in  a 
palsied  part. 

The  temperature  of  that  cat  was  at  the  ordinary  degree,  (105° 
.Eahr.,  in  the  rectum.)  The  secretion  of  the  hair  and  nails  took 
place  as  in  healthy  cats.  I  had  previously  seen  on  birds  that 
their  temperature  remained  normal  after  the  destruction  of  a 
great  part  of  the  spinal  cord.  Besides,  I  have  found  in  these 
birds  that  the  secretion  of  quills  and  nails  continued  to  take  place. 

As  to  the  influence  of  the  medulla  oblongata  on  the  functions 
of  organic  life,  my  experiments  on  cold-blooded  vertebrata  have 
proved  to  me,  that  these  functions  (except,  of  course,  pulmonary 
respiration,)  may  continue  to  exist  without  any  appearance  of 
disturbance. 

5.  After  the  complete  transverse  section  of  the  spinal  cord  in 
mammals  or  birds,  I  have  found  that  the  ulcerations  which  take 
place  around  the  genital  organs  do  not  result  directly  from  the  ab- 
sence of  nervous  action.  One  of  the  causes  of  these  ulcerations 
is  continued  pressure,  and  another  cause  is  the  continual  pre- 
sence of  altered  urine  and  faeces. 

*  See  Med.  Exam.,  No.  v.  May,  1852,  p.  321. 


16 

My  opinion  is  well  proved  by  the  following  experiments : — 

1st.  I  have  put,  three  or  four  times  a  day  and  for  many  days, 
a  certain  quantity  of  urine  on  the  posterior  part  of  the  neck,  in 
the  neighborhood  of  the  scapulae,  upon  guinea-pigs.  Before  a 
week  elapsed,  the  skin,  at  the  place  acted  on  by  the  urine,  had 
lost  its  hair  and  epidermis.  After  a  week  more  there  was  an 
ulceration  in  the  skin,  and  ten  or  twelve  days  later  the  skin  was 
destroyed,  and  there  was  an  ulcer  with  a  very  bad  aspect.  This 
fact  proves  how  powerful  is  the  action  of  urine  on  the  skin. 

2d.  On  guinea-pigs,  upon  which  the  spinal  cord  was  cut  in  the 
dorsal  region,  and  on  pigeons,  upon  which  the  spinal  cord  was 
destroyed  from  the  fifth  costal  vertebra  to  its  termination,  I  have 
found  that  no  ulceration  appeared  when  I  took  care  to  prevent 
any  part  of  their  bodies  from  being  in  a  continued  state  of  com- 
pression, and  of  washing  them  many  times  a  day  to  remove 
the  urine  and  faeces. 

3d.  In  cases  where  an  ulceration  had  been  produced,  I  have 
succeeded  in  curing  it  by  washing  and  preventing  compression. 

4th.  I  have  found  that  in  animals  having  the  spinal  cord  cut 
across,  every  kind  of  wounds  or  burns  were  cured  as  quickly  as 
in  healthy  animals. 

Therefore  the  ulcerations  which  appear,  in  cases  of  paraplegia, 
do  not  exist  -directly  in  consequence  of  the  palsy  ;  they  can  be 
avoided  and  in  many  cases  they  can  be  cured. 

These  conclusions  are  perfectly  true  in  animals  having  had 
an  injury  to  the  spinal  cord  for  a  shorter  time  than  a  year ; 
but  on  guinea-pigs,  upon  which  a  lateral  half  of  the  spinal  cord, 
had  been  cut  for  fourteen,  fifteen,  or  eighteen  months,  near 
the  tenth  or  eleventh  costal  vertebra,  I  have  found  an  alteration 
of  nutrition  in  the  palsied  parts.  It  was  the  right  half  of  the 
spinal  cord  which  had  been  cut,  and  in  such  a  case,  as  I  have 
discovered,  the  left  side  of  the  body  behind  the  wounded  part 
evidently  loses  a  portion  of  its  sensibility,  and  its  temperature  is 
also  diminished.  I  have  found,  at  the  time  designated,  an  ulcera- 
tion coming  in  the  part  between  the  sacrum  and  the  hip-joint. 
That  ulceration  has  taken  a  tolerably  great  extension  in  surface 
but  not  in  depth.  It  became  as  large  as  a  half  dollar. 
The  part  ulcerated  has  never  been  subjected  to  any  kind  of 
compression,  neither  to  the  action  of  urine  and  faeces. 


17 

Another  kind  of  disturbance  of  nutrition  occurred  in  these 
animals  :  they  lost  the  hair  of  the  leg,  and  of  the  other  parts  in 
which  the  sensibility  was  diminished. 

6.  It  is  known  tliat  erection  is  a  frequent  phenomenon  in  men 
after  a  fracture  or  a  luxation  of  the  vertebral  column.  It  is 
known  also,  that  in  men  hanged,  erection  and  even  ejaculation 
are  not  uncommon.  Segalas  says  he  has  seen  these  phenomena 
produced  by  the  excitation  of  the  spinal  cord.  Longet  (loco 
cit.,  p.  201,)  declares  that  he  has  not  seen  the  excitation  of  the 
cord  producing  such  effects.  It  is  very  easy  to  ascertain,  on 
male  guinea-pigs,  that  Segalas  is  right. 

1st.  A  transverse  section  of  the  spinal  cord  always  produces 
an  erection  and  an  ejaculation. 

2d.  When  one  of  these  animals  is  asphyxiated,  erection  and 
ejaculation  take  place. 

3d.  If  the  spinal  cord  is  galvanized,  erection  and  ejaculation 
are  produced. 

These  facts  prove  the  influence  of  the  spinal  marrow  on  the 
seminal  vesicles.  They  empty  themselves  slowly  when  the  cord 
is  galvanized. 

In  asphyxia,  there  are  universal  convulsions  even  in  the  mus- 
cles of  organic  life,  as  uterus,  intestine,  etc.  These  last  organs 
are  then  put  in  contraction,  and  it  is  not  astonishing,  conse- 
quently, that  the  seminal  vesicles  become  also  contracted.  The 
cause  of  these  general  contractions  is  the  excitation  of  the  spinal 
cord  by  venous  blood,  and  very  probably  by  a  large  amount  of 
carbonic  acid,  as  I  will  elsewhere  try  to  demonstrate. 

IV. — ON   THE   REPARATIVE   POWER   OF  THE  NERVOUS   SYSTEM. 

I  have  recently  published  in  this  journal*  the  results  of  my  re- 
searches on  the  reparative  power  of  the  spinal  cord.  From  these 
researches  I  have  drawn  the  following  conclusions : — 

1st.  That  the  spinal  marrow,  even  in  adult  mammalia,  may  be 
exposed  to  the  action  of  the  air  without  danger  to  the  life  of  the 
animal. 

2d.  That  wounds  of  the  spinal  marrow  may  be  repaired. 

*  Med.  Exam.,  No.  vi.,  June,  1852,  p.  379. 

2* 


18 

3d.  That  after  a  complete  transverse  section  of  the  spinal 
cord,  the  functions  of  that  organ  may  be  entirely  restored. 

As  to  the  nerves,  the  experiments  of  Fontana,  Haighton, 
Tiedemann,  Flourens,  Steinrueck,  and  many  others,  have  de- 
monstrated the  possibility  of  reunion  of  the  two  extremities  of  a 
cut  nerve.  But,  in  most,  if  not  in  all  these  experiments,  the  re- 
turn of  sensibility  and  of  voluntary  movements  have  not  been 
complete.  The  following  fact  is,  consequently,  very  important, 
because  it  proves  the  possibility  of  a  complete  reappearance  of  the 
lost  faculties  after  the  entire  division  of  a  nerve.* 

A  guinea-pig,  on  which  the  sciatic  nerve  had  been  cut  across, 
exhibited  indications  of  a  return  of  sensibility  a  month  after  the 
operation.  Two  months  afterwards  the  sensibility  was  increased, 
but  was  still  much  inferior  to  that  of  the  sound  limb.  The  mus- 
cles then  were  beginning  to  contract  under  the  influence  of  the 
will.  Six  months  after  the  section,  the  animal  could  evidently 
move  its  legs  and  toes  voluntarily ;  the  sensibility  then  was  almost 
entirely  recovered.  At  the  end  of  about  eleven  months,  the 
sensibility  and  all  the  voluntary  movements  were  apparently 
alike  in  the  two  posterior  limbs.  The  animal  having  been  killed, 
it  was  found  by  my  friend  Dr.  Lebert  and  myself  that,  except 
a  slight  union  of  muscular  fibres  with  the  nerve  at  the  place 
where  it  had  been  divided,  the  restoration  of  the  original  condi- 
tion was  so  complete  that  no  indication  of  the  division  could  be 
discovered,  either  with  the  naked  eye  or  with  the  microscope.  I 
had  seen  the  usual  swelling  of  the  nerve  at  the  point  of  reunion 
about  the  sixth  month  after  the  operation,  but  at  the  time  of  the 
last  examination  it  had  disappeared. 

V. — ON    TURNING    AND    ROLLING    AS    PHENOMENA    PRODUCED    BY 
INJURIES   OF   THE    NERVOUS    SYSTEM. 

Pourfour  du  Petit  and  Me'he'e  de  la  Touche  were  the  first  expe- 
rimenters who  witnessed  turning  produced  by  an  injury  of  the 
nervous  centres.  But  the  first  valuable  researches  on  this  phe- 
nomenon were  made  by  Magendie  and  Flourens. 

The  parts  of  the  cerebro-spinal  centre  which  can  be  injured 
without  producing  turning,  are :  the  cerebral  hemispheres,  the 

*See  Gaz.  Med.  de  Paris,  1849,  t.  iv.  p.  880. 


19 

cerebellum,  the  corpora  striata,  the  corpus  callosum,  the  spinal 
marrow  and  the  olfactive  and  optic  nerves.*  All  the  other  parts 
of  the  cerebro-spinal  centres  are  able  to  produce  turning  or  roll- 
ing. 

These  circulatory  or  rotatory  movements  take  place  sometimes 
on  the  same  side,  and  sometimes  on  the  side  of  the  body  opposite 
to  that  of  the  encephalon  which  has  been  injured. 

A  puncture  of  one  of  the  following  parts  produces  turning  or 
rolling  on  the  injured  side : 

1st.  The  anterior  extremity  of  the  thalami  optici,  according 
to  Schiff. 

2d.  The  crura  cerebri,  according  to  Magendie. 

3d.  The  bi,  or  quadri-geminal  tubercles,  according  to  Flourens. 

4th.  The  pons  varolii. 

5th.  The  posterior  part  of  the  processus  cerebelli  ad  pontem. 

6th.  The  auditive  nerve,  according  to  my  own  experiments. 

7th.  The  medulla  oblongata  at  the  point  of  insertion  of  the 
facial  nerve,  according  to  my  experiments  in  common  with  Dr. 
Martin-Magron. 

8th.  The  medulla  oblongata  outside  of  the  anterior  pyramids, 
according  to  Magendie. 

9th.  A  great  part  of  the  posterior  face  of  the  medulla  ob- 
longata, according  to  my  experiments. 

The  parts  of  the  encephalon  which  produce  turning  or  rolling 
on  the  opposite  side,  are  : 

1st.  The  posterior  extremity  of  the  thalami  optici,  according 
to  Schiff. 

2d.  The  crura  cerebri,  according  to  Lafargue. 

3d.  The  anterior  part  of  the  processus  cerebelli  ad  pontem. 

4th.  A  small  part  of  the  medulla  oblongata  before  the  nib  of 
the  calamus  scriptorius  and  behind  the  corpora  olivaria,  accord- 
ing to  my  experiments  in  common  with  Dr.  Martin-Magron. 

Some  of  these  two  series  of  parts  ordinarily  produce  turning 
and  the  others  rolling.  But  these  two  kinds  of  movements  can 
be  produced  by  the  puncture  of  a  single  part  of  the  encephalon. 
Rolling  is  nothing  but  the  exaggeration  of  turning ;  thus,  after 

*  I  consider  as  a  part  of  the  nervous  centres,  the  three  nerves  of  the  su- 
perior senses :  the  olfactive,  the  optic  and  the  auditive. 


20 

a  puncture  of  the  medulla  oblongata,  the  animal  at  first  rolls,  and 
after  some  instants,  instead  of  rolling,  it  turns.  If,  when  it  is 
turning,  a  slight  puncture  is  made  anew,  close  to  the  first,  then 
the  animal  rolls. 

Before  trying  to  explain  turning,  I  will  give  an  outline  of 
some  of  its  species. 

1st.   Turning  and  Rolling  caused  by  tearing  the  facial  nerve. 

My  friend  Dr.  Martin-Magron  and  myself  have  discovered 
that  if  the  facial  nerve  of  a' rabbit  or  a  guinea-pig  be  exposed  at 
its  exit  from  the  stylo-mastoid  foramen,  and  be  then  drawn  away 
from  the  cranium,  so  as  to  tear  it  asunder  near  its  origin,  the 
animal  begins  in  about  five  minutes  to  turn  itself  round  and 
round,  the  movement  being  from  left  to  right  when  the  nerve 
has  been  thus  torn  on  the  left  side,  and  from  right  to  left  when 
it  has  been  torn  on  the  right  side.  This  rotation  is  generally 
preceded  by  convulsive  movements  of  the  eyes,  of  the  jaws,  and 
of  the  head  upon  the  trunk :  and  the  body  is  then  bent  (as  in 
pleurosthotonos)  towards  the  injured  side,  by  the  contraction  of 
all  the  longitudinal  muscles  of  that  side,  the  power  of  which  is 
such  as  to  resist  considerable  force  applied  to  extend  them.  The 
movement  at  first  takes  place  in  a  small  circle ;  but  the  circle 
generally  enlarges  more  and  more,  until  at  last,  after  twenty  or 
thirty  minutes,  the  animal  walks  in  a  straight  line.  There  is  no 
paralysis  of  any  muscles,  save  the  facial.  The  effect  is  not  pro- 
duced, unless  the  nerve  be  torn  close  to  its  origin. 

When  the  nerve  on  the  other  side  also  is  torn,  even  after  a 
long  interval,  instead  of  the  tendency  to  turn  to  one  side,  there 
is,  at  first,  a  rolling  of  the  body  on  its  longitudinal  axis,  which 
takes  place  towards  the  side  last  operated  on.  After  this  has 
continued,  however,  for  twenty  minutes  or  more,  the  animal 
recovers  its  feet,  and  begins  to  turn,  as  after  the  first  operation, 
but  towards  the  other  side.  This  movement  soon  ceases. 

Dr.  Martin-Magron  and  myself  think  that  the  cause  of  these 
phenomena  does  not  exist  in  the  facial  nerve  itself,  but  in  the 
part  of  the  medulla  oblongata  from  which  this  nerve  has  origi- 
nated.* 

*  See  Gaz.  Med.  de  Paris,  1849,  t.  4,  p.  879. 


2i 

2d.   Turning  and  Rolling  produced  by  an  injury  to  the  Medulla 

Oblong  ata. 

M.  Magendie  (Precis  Ele'm.  de  Physiol.  Paris,  1836,  t.  1,  p. 
414)  says :  "  Having  raised  up  the  cerebellum,  I  make  a 
section  perpendicularly  to  the  surface  of  the  fourth  ventricle  and 
at  three  or  four  millimetres  from  the  median  line.  If  I  cut  on 
the  right,  the  animal  will  turn  on  the  right  side  ;  if  I  cut  on  the 
left,  it  will  turn  on  the  left  side." 

If  we  suppose  a  plane  cutting  the  medulla  oblongata  transversely 
at  the  distance  of  nearly  two  lines  before  the  nib  of  the  calamus 
scriptorius,  the  posterior  face  of  the  medulla  oblongata  will  be 
divided  into  two  parts :  one  before  that  plane,  which  I  will  call 
superior,  and  the  other  behind,  or  inferior. 

Now,  every  puncture  on  that  superior  part  produces  turning 
or  rolling  on  the  side  which  has  been  punctured.  The  slightest 
puncture  on  the  processes  cerebelli  ad  medullam  oblongatam  is 
able  to  produce  a  violent  and  very  rapid  rolling.  As  long  as  the 
animal  lives  after  the  operation,  it  rolls  or  it  turns  at  each  time  it 
tries  to  walk. 

When  (as  Dr.  Martin-Magron  and  myself  have  discovered)  a 
deep  section  is  made  on  the  inferior  part  of  the  posterior  face  of 
the  medulla  oblongata,  before  the  nib  of  the  calamus  scriptorius, 
turning  is  produced  on  the  side  of  the  body  opposite  to  the  punc- 
tured side  of  the  medulla.  A  rabbit,  which  has  lived  thirteen 
days  after  the  operation,  had  still  the  circulatory  movement  a 
few  hours  before  dying.  Nevertheless,  sometimes  the  animal 
could  walk  nearly  straight  during  a  few  seconds. 

3d.  Turning  Produced  by  a  Puncture  or  a  Section  of  the 
Acoustic  Nerve. 

Flourens  has  discovered  that,  after  the  section  of  the  semi- 
circular canals,  turning  sometimes  takes  place. 

I  have  found  all  the  facts  he  relates  about  this  subject  perfectly 
right.  It  was  interesting  to  know  if  a  puncture  or  the  section 
of  the  auditive  nerve  would  produce  turning.  As  it  was  impos- 
sible to  operate  on  that  nerve  in  mammals,  I  have  experimented 
on  frogs.  In  these  amphibia  it  is  easy  to  find  the  nerve  and  to 
act  upon  it.  I  have  found  that  after  a  puncture  or  a  section  on 
the  trunk  of  the  nerve,  the  animal  begins  instantly  to  turn.  As 


22 

long  as  the  frogs  live,  after  a  puncture  of  the  acoustic  nerve,  they 
turn  ;  but  the  circle  of  turning  is  much  smaller  a  short  time 
after  the  operation  than  afterwards.  I  have  kept  such  frogs 
for  months. 

4th.   On  a  New  Mode  of  Turning. 

I  have  found  a  mode  of  turning  which  has  altogether  some  of 
the  characters  of  turning  and  of  rolling. 

In  the  circulatory  movement  called  turning  (mouvement  de 
manege),  the  body  of  the  animal  is  bent  on  one  of  the  lateral 
sides.  It  has  the  shape  of  an  arch,  and  this  arch  is  generally  a 
part  of  the  circumference  described  by  the  animal  when  turning. 
The  smaller  the  radius  of  that  arch,  the  smaller  is  the  circle  of 
turning. 

In  the  new  mode  of  turning  I  have  found,  the  body  of  the 
animal  is  not  bent,  and  when  it  walks  it  moves  laterally, 
instead  of  going  forwards.  In  turning  it  describes  a  circle,  but 
the  longitudinal  axis  of  its  body,  instead  of  being  then  a  part  of 
the  circumference,  is  a  part  of  a  radius,  so  that  its  head  is  at  the 
circumference,  and  its  tail  towards  the  centre  of  the  described 
circle. 

That  mode  of  turning  has  been  executed  by  animals  on  which 
the  quadrigeminal  tubercles  and  the  pons  varolii,  on  one  side, 
had  been  punctured  by  a  pin.  One  of  the  eyes  was  convulsed  ; 
the  other  was  in  its  normal  condition.  The  convulsed  eye  was 
the  right  one,  and  the  tubercles  punctured  were  those  of  the 
left  side. 

5th.   On  the  Causes  of  Turning  and  Rolling. 

I  have  not  room  enough  to  show  that  the  theories  of  Magendie, 
Flourens,  Henle,  Lafargue  and  Schiffare  contradicted  by  a  great 
many  facts.  I  will  only  present  the  following  remarks : 

1st.  As  the  slightest  puncture  of  certain  parts  of  the  encepha- 
lon  is  sufficient  to  produce  turning  or  rolling,  it  is  evident  that 
those  rotating  movements  do  not  exist  in  consequence  of  an 
hemiplegia,  as  Lafargue,  Longet  and  SchifF  believe  they  do. 
Another  reason  is  that  every  degree  of  hemiplegia  exist  in  man 
without  being  accompained  by  turning  or  rolling.  Besides,  these 
phenomena  have  been  observed  in  persons  who  had  no  paralysis 
at  all. 


23 

2d.  The  theories  of  Magendie  and  Flourens  are  also  opposed, 
by  the  fact  that  a  slight  puncture  is  sufficient  to  produce  turning 
or  rolling. 

3d.  As  to  the  theory  of  Henle,  which  is  based  upon  the 
existence  of  convulsions  in  the  eye,  producing  a  kind  of  vertigo, 
it  has  against  it  the  facts  that,  on  one  side,  convulsions  may 
exist  in  the  eyes  without  any  other  disorder  in  the  movements ; 
and,  on  the  other  side,  sometimes  turning  or  rolling  exist  with- 
out any  convulsion  in  the  eyes.* 

Nevertheless,  I  think  that,  in  many  cases,  the  vertigo  conse- 
quent on  convulsions  of  the  eyes  is  one  element  of  the  cause  of 
turning.  I  think  also  that,  in  certain  cases,  paralysis  of  some 
parts  of  the  body  may  facilitate  the  rotatory  movements.  But 
their  great  cause,  I  think,  is  the  existence  of  a  convulsive 
contraction  in  some  of  the  muscles,  on  one  side  of  the 
body.  These  convulsive  contractions  are  to  be  found  in 
every  case  of  circulatory  or  rotatory  movement.  As  to  the  cause 
of  these  contractions,  it  exists  in  the  irritation  produced  in  cer- 
tain parts  of  the  encephalon. 

VI. — ON    A    MEANS  OP   MEASURING  DEGREES  OF  ANAESTHESIA  AND 
HYPER^STHESIA. 

The  curious  facts  discovered  by  E.  H.  Weber,  on  tactile  sen- 
sibility, are  well  known.  He  found  that  if  the  two  blunted 
points  of  a  pair  of  compasses  are  applied  simultaneously  on  the 
skin,  there  is,  according  to  certain  circumstances,  either  the 
sensation  of  one  or  of  two  points.  When  the  points  are  both 
inside  of  certain  boundaries,  they  are  felt  as  one  only ; 
when  they  are  outside  of  these  boundaries,  both  are  felt. 
These  boundaries  vary  exceedingly  in  different  parts  of  the 
skin,  but  for  a  given  part  the  differences  between  men  are 
not  extremely  considerable.  I  have  made  use  of  the  compasses 
for  measuring  the  degrees  of  tactile  sensibility  in  diseases.  In  a 
case  of  considerable  anaesthesia  of  the  lower  extremities,  the 
patient  only  felt  a  single  impression  on  one  leg,  although  the 

*  See  a  very  remarkable  case  observed  by  my  friend  Dr.  Lebret,  in 
Comptes  rendus  et  Memoires  de  la  Soc.  de  Biologic  annee  1850.  Paris, 
1851.  t.  ii.  p.  7. 


24 

points  of  the  compasses  were  ten,  fifteen,  or  even  twenty  centi- 
metres apart ;  whilst  on  the  other  leg  he  could  distinguish  them 
at  a  distance  of  twelve  centimetres.  The  normal  limit  is  gene- 
rally, for  that  limb,  from  three  to  five  centimetres.  In  another 
case  where  anaesthesia  was  slighter,  the  limit  of  the  discriminat- 
ing power  was  at  from  nine  to  sixteen  centimetres.  In  two  other 
cases,  in  which  the  diminution  of  sensibility  had  not  been  found 
by  the  other  means  of  diagnosis,  the  compass  indicated  a 
very  slight  and  beginning  anaesthesia.  The  limit  was  at  from 
six  to  seven  centimetres.  • 

These  facts,  and  many  others,  have  demonstrated  to  me  that  by 
the  help  of  the  compass,  a  physician  can  ascertain  :  1st.  Whether 
there  is  a  slight  anaesthesia  or  no.  2d.  What  is  the  degree  of 
anaesthesia.  3d.  What  changes  occur  every  day  in  the  amount 
of  anaesthesia. 

The  same  is  true  for  the  cases  of  hyperaesthesia.  In  a  case  of 
paraplegia  of  the  motor  power,  the  patient  felt  the  two  points  of 
the  compasses,  on  his  feet,  even  at  the  distance  of  five  millime- 
tres, whilst  a  healthy  person  feels  the  two  points  only  when  they 
are  at  a  greater  distance  than  twenty-five  millimetres. 

I  shall  add,  that  for  succeeding  in  such  experiments  the  two 
points  must  be  blunted  and  applied  simultaneously.* 

*  See  Gaz.  Med.  de  Paris,  1849,  t.  iv.  p.  1012. 


25 


VII ON  THE  CAUSES  OF  THE  TORPIDITY  OF  THE  TENREC,  (JErina- 

ceus  ecaudatuSj  Linn.) 

The  influence  of  cold  as  a  cause  of  hybernation  has  not  been 
considered  essential,  on  account  of  an  assumed  fact,  which  is 
altogether  incorrect.  This  fact  is  that  a  mammal  called  the 
Tenrec,  (Erinaceus  ecaudatus,~Lm.,)  which  lives  in  the  Islands  of 
Mauritius,  of  Madagascar  and  Bourbon,  is  torpid  under  the 
joined  influences  of  warmth  and  dry  ness.  Cuvier  says,  about  the 
Tenrec :  "  They  are  nocturnal  animals,  remaining  in  lethargy 
three  months  each  year,  although  they  inhabit  the  torrid  zone. 
Moreover,  Bruguiere  asserts  that  it  is  during  the  time  of  the 
greatest  heat  that  they  are  torpid."  Physiologists  have  admit- 
ted this  fact  as  true,  and  they  have  supposed  that  warmth  and 
dryness  could  be,  like  cold,  a  cause  of  torpidity. 

The  following  facts  prove  that  the  torpid  sleep  of  the  tenrec 
takes  place  from  precisely  the  same  cause  as  that  of  the 
hedge-hog,  LErinaceus  Europeus,  Lin.,)  and  of  other  hyber- 
nating  mammals : 

1st.  The  tenrec  and  the  hedge-hog  belong  to  the  same 
family,  and  they  are  much  alike. 

2d.  According  to  MM.  Desjardins,  Telfair  and  Coquerel,  and 
to  my  own  observations,  the  tenrecs  earth  themselves,  and  are 
torpid  from  the  month  of  June  to  the  month  of  November,  i.  e. 
during  the  winter  season  of  the  Islands  where  they  live. 

3d.  Hybernating  animals,  belonging  to  varied  species, 
observed  by  Pallas,  Mangili,  Marshall  Hall,  Berthold,  Barkow, 
and  myself,  have  been  found  torpid  at  the  temperature  of  61  to 
66°  F.,  (16  to  19°  Cs.)  Moreover,  I  have  found  that  dormice, 
(Mus  glis.,  Lin.)  even  at  a  temperature  of  6 S  to  72°  F.,  (20  to 
22°  Cs.)  may  become  torpid,  and  I  have  observed  some  that 
were  constantly  sleeping,  during  a  whole  week,  at  a  tem- 
perature varying  from  59  to  68°  F.  (15  to  20°  Cs.)  I  have 
stated  that  hedge-hogs  may  be  torpid  during  the  summer ; 
in  Paris,  at  a  temperature  of  68  to  72°  F.,  (20  to  22°  Cs.)  and 
lately,  in  Philadelphia,  I  have  seen  a  marmot  (Arctomys  monax, 
Buff.)  torpid,  in  June,  at  a  temperature  of  71  to  73°  F.  (21.5  to 
23°  Cs.) 

4th.  During  the  time  of  its  torpidity,  the  tenrec  is  under 

3 


26 

the  influence  of  a  temperature  of  59  to  72  or  73°  F.,  (15  to  22 
or  23°  Cs.)  rarely  more,  and  sometimes  less.  Therefore  these 
animals  are  exposed  to  a  temperature  sufficiently  low  to  render 
them  torpid,  for  that  temperature  may  produce  that  effect  on 
the  hybernating  animals  of  cold  countries. 

From  these  facts  I  believe  it  is  right  to  conclude  that  torpidity 
is  induced  in  the  tenrec,  in  the  same  way  as  in  the  other  hyber- 
nating mammals,  and  therefore  it  is  not  necessary  to  suppose 
that  warmth  and  dryness  produce  torpidity. 

VIII ON  THE  INFLUENCE  OF   POISONS  UPON  ANIMAL   HEAT   AS   A 

CAUSE  OF  DEATH. 

Provost  and  Chossat,  and  after  them,  M.  Magendie,  have 
ascertained  that  death  occurs  quickly  in  mammals  when  their 
temperature  is  notably  diminished.  My  experiments  confirm 
the  correctness  of  that  statement.  The  diminution  of  animal 
heat  in  mammals,  is  so  dangerous  that,  in  one  case,  I  have  seen 
death  take  place  in  a  rabbit  after  a  diminution  of  only  22°  F. 
(12°  Cs.)  I  have  never  observed  any  animal  continuing  to  live 
when  I  had  diminished  its  temperature  more  than  44°  F.  (24°.5 
Cs.)  I  have  found  the  law  established  by  Chossat  perfectly  correct, 
according  to  which  the  diminution  of  animal  heat  necessary  for 
killing  is  less  and  less,  in  proportion  to  the  rapidity  with  which 
that  diminution  takes  place. 

It  is  very  probable  that  in  all  the  cases  where,  in  consequence 
either  of  disease,  or  of  a  wound,  or  of  poison,  the  tem- 
perature of  man  is  diminished  many  degrees,  his  life  is  in 
danger  from  the  very  fact  of  that  diminution.  It  is  thus  in 
cholera,  in  sclerema,  in  certain  cases  of  palsy,  in  cases  of  great 
disturbance  of  the  respiration,  in  fractures  and  luxations  of  the 
vertebral  column,  in  the  cervical,  and  even  in  the  dorsal  regions, 
in  cases  of  profuse  haemorrhage,  and  in  many  cases  of  poisoning 
when  death  is  not  rapidly  produced. 

It  has  been  long  known  that  temperature  is  diminished  in 
poisoned  persons  ;  and  there  are  but  few  cases  of  poisoning  on 
record  in  which  it  is  not  said  that  the  patient  was  cold.  Chos- 
sat has  found  that  a  dog,  into  whose  veins  he  had  injected 
opium,  had  its  temperature  diminished  from  105°  to  62.6°  F. 
(40°.3  to  17°  Cs.),  22  hours  after  the  injection.  Brodie  has 


found  that  many  poisons  act  upon  animal  heat  so  as  to  diminish 
it  considerably.  Demarquay  and  Dume'ril,  junior,  and  later, 
these  two  experimenters,  joined  with  Lecointre,  have  found  the 
same  thing  as  Brodie  in  many  toxic  agents.  I  have  made 
very  numerous  experiments  on  this  subject,  and  some  of  their 
results  have  been  published  before  the  last  papers  of  Demarquay, 
Dume'ril  and  Lecointre.* 

I  have  stated  that  many  poisons,  either  injected  in  the  veins 
or  absorbed  by  the  vessels  of  the  skin  or  of  the  digestive  canal, 
may  diminish  sufficiently  the  temperature  of  Guinea  pigs 
and  rabbits,  to  produce  death.  This  occurs  when  the  dose  of 
the  poison  is  not  large  enough  to  kill  in  less  than  four  or 
five  hours.  These  poisons  may  kill  only  by  their  action  upon 
animal  heat.  It  may  be  so  with  opium,  cyanhydric  acid,  the 
cyanide  of  mercury,  hyoscyamus,  digitalis,  belladonna,  tobacco, 
euphorbia,  camphor,  alcohol,  acetic,  oxalic,  sulphuric,  azotic, 
chlorohydric  acids  much  diluted,  and  some  oxalates. 

Of  course  the  action  of  these  poisons  is  the  greater,  the  colder 
the  atmosphere ;  but  it  is  not  always  immediately  so,  and  in- 
stead of  diminishing  the  animal  heat,  many  may  increase  it 
for  a  time,  especially  when  the  temperature  of  the  atmosphere 
is  elevated. 

I  have  discovered  that  a  dose  of  one  of  these  poisons,  suf- 
ficient to  kill  an  animal,  when  there  is  no  obstacle  to  the  dimi- 
nution of  its  temperature,  may  be  unable  to  destroy  life  when  the 
temperature  of  the  animal  is  maintained  by  artificial  means  to 
its  normal  degree,  or  not  far  from  it.  My  experiments  have 
been  conducted  as  follows : 

Equal  doses  of  poison  were  given,  simultaneously,  to  two  ani- 
mals, as  much  alike  one  another  as  possible.  One  of  them 
was  left  in  a  room  at  a  temperature  of  from  46  to  50°  F.  (8  to 
10°  Cs.),  and  the  other  was  kept  not  far  from  a  chimney,  in  a 
place  where  the  air  was  at  from  75  to  86°  F.  (24  to  30°  Cs.) 
The  first  was  dead  after  a  certain  number  of  hours,  or  sometimes 
one  or  two  days,  having  its  temperature  much  diminished.  The 
other,  on  the  contrary,  had  no  perceptible  diminution  of  its 
temperature,  and  was  generally  cured  very  soon.  Therefore, 

*  See  Gaz.  Med.  de  Paris,  1849,  t.  iv.,  p.  644. 


28 

when  taken  in  certain  doses,  many  poisons  may  kill  only  by 
their  influence  on  animal  heat,  and  physicians,  in  cases  of  poison- 
ing, should  try  as  much  to  prevent  the  diminution  of  tempera- 
ture, as  to  expel  the  poison  or  to  act  against  it  by  an  antidote, 
by  pulmonary  insufflation,  or  otherwise. 

In  experiments  which  I  have  made  lately  on  the  action  of 
very  pure  digitaline,  that  had  been  prepared  by  M.  Quevenne, 
the  celebrated  chemist,  who  has  made  such  interesting  and 
accurate  researches  on  digitalis  and  the  substances  of  which  it 
is  composed,  I  have  found  that  this  poison  may  also  dimmish 
temperature.  I  believe  it  is  easy  to  explain  the  contradiction 
existing  between  Traube  and  Stannius,  as  regards  the  influ- 
ence of  digitalis  on  animal  heat.  When  the  atmosphere,  in 
which  the  animal  is,  is  cold,  then  its  temperature  may  be  dimin- 
ished by  digitalis  or  digitaline,  but  when  it  is  warm  the  diminu- 
tion does  not  take  place,  or  it  is  very  small.  But,  of  course,  if 
the  dose  is  sufficient  to  kill  very  quickly,  then  it  is  indifferent 
whether  the  atmosphere  is  cold  or  not,  because  there  may  be  not 
time  enough  for  the  diminution  of  the  temperature  of  the  animal. 

I  have  to  relate  another  fact  which,  I  believe,  ought  to  be 
considered  as  analogous  to  the  preceding.  It  is  that  kind  of 
poisoning  which  occurs  when  a  layer  of  oil,  of  varnish  or  of 
gelatin,  is  put  on  the  skin  of  a  warm-blooded  animal.  Death, 
then,  is  very  probably  produced  by  a  substance  unknown 
until  now,  and  which  is  secreted  by  the  skin.  The  layer  of  oil, 
varnish,  or  gelatin  preventing  that  secretion  taking  place,  that 
unknown  substance  becomes  accumulated  in  the  blood,  and  then 
are  produced  the  phenomena  so  well  studied  by  MM.  Fourcault, 
Becquerel,  Breschet,  and  Magendie.  I  have  found  that  in 
such  a  case  the  animals  may  live,  if  the  atmosphere  in  which 
they  are  kept  is  at  a  temperature  inferior  to  79  or  80°  F.  (26  or 
27°  Cs.)  In  these  circumstances  their  temperature  is  not  sensi- 
bly diminished,  while  it  diminishes  much  when  the  atmosphere 
is  cold.  Therefore  it  is  especially  by  their  loss  of  warmth  that 
animals  are  killed,  when  their  body  has  been  entirely  covered 
with  oil,  varnish,  or  gelatin. 


29 


IX. — ON  CERTAIN  ACTIONS  OF  COLD,  WARMTH,  AND  LIGHT  UPON  THE 
CRYSTALLINE  LENS. 

Pourfour  du  Petit  has  discovered  that  after  the  death  of  a 
mammal,  it  is  not  uncommon  to  find  the  crystalline  lens  opaque. 
He  has  found  also,  that  when  the  lens  has  become  opaque,  if  we 
draw  it  near  the  flame  of  a  candle  or  a  lamp,  it  becomes  trans- 
parent again  after  a  few  minutes.  The  same  lens,  put  alter- 
nately near  and  far  from  the  flame,  may  become  alternately 
transparent  and  opaque.  I  have  endeavored  to  discover  whether 
it  is  the  light  or  the  warmth  of  the  flame  which  renders  an  opaque 
lens  transparent.  I  have  placed  between  the  lens  and  the  flame 
a  layer  of  mineral  salt,  which  is  athermane  and  transparent. 
Then  the  light  of  the  flame  could  reach  the  lens,  but  not  its 
warmth.  There  has  been  no  action.  In  another  experiment  I 
have  exposed  to  the  light  passing  through  the  mineral  salt  a 
fresh  crystalline  lens,  still  perfectly  transparent.  It  became 
opaque.  Now,  in  a  third  experiment,  I  have  compared  two 
crystalline  lenses,  perfectly  transparent,  one  exposed  to  the 
action  of  light  passing  through  the  mineral  salt,  and  the 
other  kept  in  an  obscure  place.  The  former  became  opaque 
much  quicker,  and  considerably  more  than  the  other.  There- 
fore, 1st.  It  is  not  light  which  renders  transparent  an  opaque 
lens ;  2d.  Light  does  not  prevent  a  transparent  lens  from  be- 
coming opaque  ;  3d.  Moreover,  light  appears  to  accelerate,  if 
not  to  produce,  the  opacification  of  the  crystalline  lens. 

As  to  the  influence  of  warmth,  it  is  certain  that  it  is  that 
which  renders  transparent  an  opaque  lens :  1st.  When  left  in 
the  atmosphere,  at  a  temperature  superior  to  70°  F.  (21°  Cs.),  a 
fresh  transparent  lens  remains  transparent.  2d.  When  a  lens 
has  become  opaque,  it  is  frequently  sufficient  to  keep  it  exposed 
to  the  warmth  of  the  hand,  during  some  minutes,  to  render  it 
transparent.  3d.  The  lower  the  temperature  of  the  atmosphere 
the  quicker  transparent  lenses  become  opaque. 

These  experiments  give  a  very  interesting  result,  i.  e.,  that 
light  appears  able  to  produce  an  effect  precisely  opposite  to  the 
effect  produced  by  warmth. 

From  these  researches  I  conclude  : 

1st.  That  light,  and  a  low  temperature,  are  favorable  condi- 

3* 


30 

tions,  if  not  direct  causes,  of  the  opacity  of  the  lens  in  warm- 
blooded animals  after  death. 

2d.  That  a  warm  temperature,  i.  e  ,  a  temperature  superior  to 
70°  F.  (21°  Cs.)  is  &  cause  of  the  change  occurring  in  the  lens, 
by  which,  when  opaque,  it  becomes  transparent. 

I  will  add,  that  sometimes  an  analogous  opacity  takes  place  in 
the  cornea. 

X. — ON  THE  NORMAL  DEGREE  OF  THE  TEMPERATURE  OF  MAN. 

The  degree  of  animal  heat,  in  the  human  species,  is  stated  as 
being  between  98.5°  and  100°  F.  (37  and  88°  Cs.)  I  intend  to 
prove  that  it  is  higher. 

It  is  impossible  to  take  directly  the  temperature  of  most  of 
the  internal  parts  of  the  body  in  man ;  therefore  many  physiolo- 
gists, in  order  to  discover  the  temperature  of  these  parts,  have 
argued  as  follows  :  According  to  J.  Hunter,  the  temperature 
of  the  rectum  in  animals  is  the  same  as  that  of  the  right  ven- 
tricle of  the  heart ;  hence  it  has  been  concluded  that  as  the  tem- 
perature of  the  rectum,  in  man — still  according  to  Hunter — is 
98°.42  F.  (36°.9  Cs.)  the  temperature  of  the  internal  parts  of 
the  body  ought  to  be  between  98  and  99°  F.  (36°.67  and 
37°.22  Cs.) 

Some  other  physiologists,  noting  the  temperature  of  the 
mouth  under  the  tongue,  and  supposing  that  this  temperature 
is  nearly  the  same  as  that  of  the  internal  parts  of  the  body,  have 
concluded  that  the  temperature  of  man  is  between  99  and  100°  F. 
(37°.2  and  37°.8  Cs.)  • 

We  will  prove  that  these  deductions  are  not  right : 

Firstly,  the  degree  of  the  temperature  of  the  rectum  is  not, 
as  Hunter  says,  98°.4.  It  may  be  so  in  debilitated  men,  but  in 
healthy  persons  it  is  more  elevated.  It  is  between  100  and  102°  F. 
(37.7  and  38°. 89  Cs.)  according  to  my  own  researches  and  to 
those  of  Berger  and  Maunoir.  Besides,  many  experiments  on 
dogs,  rabbits  and  guinea-pigs,  have  shown  satisfactorily  to  myself 
that  the  temperature  of  the  rectum  is  not  equal  to  that  of  the 
right  ventricle.  This  last  organ  is  from  1  to  3°  F.  (0.56  to 
1.7°  Cs.)  higher  than  the  rectum. 

The  temperature  of  the  rectum,  in  man,  being  between  100 
and  102°  F.  (37°.7  and  38°,8  Cs.),  and  the  temperature  of  the 


31 

right  ventricle,  in  man,  being  from  1  to  3°  F.  (0.56  to  1.7  Cs.) 
higher  than  that  of  the  rectum,  if  we  suppose  the  same  difference 
existing  in  man  as  in  mammals,  it  follows  that  the  temperature 
of  the  right  ventricle  of  the  heart  in  man  ought  to  be  between 
101  and  105°  F.  (38°. 33  and  40°.56  Cs.) 

But  a  closer  approximation  of  the  exact  temperature  of  the 
internal  parts  of  the  body,  in  man,  may  be  obtained  by  taking 
the  temperature  of  an  organ  situated  deeper  than  the  rectum,  and, 
consequently,  less  exposed  to  the  influence  of  the  atmosphere. 
Such  is  the  case  in  the  bladder.  I  have  observed  its  temperature 
by  taking  that  of  the  urine  at  the  moment  of  its  emission  and 
before  any  sensible  change  had  occurred  in  it.  The  urine  was 
directly  received  in  a  vase  dipped  into  a  large  quantity  of  water 
at  98°  F.  (36°.7  Cs.)  Thus  I  have  ascertained  that  the  mean 
temperature  of  the  urine,  in  man,  is  102°.6  F.  (39°.2  Cs.) 

Now  if  we  take  notice  of  this  well-known  fact,  that  the  tem- 
perature of  the  lower  part  of  the  abdomen  is  less  elevated  than 
the  upper  part,  we  are  authorized  to  believe  that  the  temperature 
of  the  central  parts  of  the  body,  in  man,  is  very  near  103°  F. 
(39°.5  Cs.) 

My  experiments  on  the  temperature  of  urine  were  made 
on  ten  strong  sailors,  in  the  spring,  on  the  Atlantic  Ocean,  be- 
tween the  43d  and  45th  deg.  of  north  latitude.  The  lowest  de- 
gree of  the  temperature  of  urine  which  I  have  observed,  was 
100°.9F.  (38°.3Cs.);  the  highest  was  103°.2F.  (39°.56  Cs.) 
My  own  urine,  examined  more  than  thirty  times,  in  the  most  va- 
ried conditions,  has  been  nearly  always  at  the  same  temperature ; 
the  variations  have  been  only  between  102°  and  102°. 8  F.  (38°.89 
and  39°33  Cs.)  The  ordinary  degree  is  102°.5  F.  (39°.17  Cs.) 

Long  before  my  researches,  the  temperature  of  urine,  in  the 
human  species,  had  been  taken  by  some  observers,  but  in  general 
without  sufficient  care.  The  temperature  of  the  urine  is  94°.25, 
according  to  Braun;  98°.9,  according  to  De  Lisle;  and  103°, 
according  to  Hales.  Recently  Berger  has  taken  the  tem- 
perature of  urine  in  the  bladder  in  five  women.  He  has  found 
it  equal  to  101°,48  F.  (38°. 6  Cs.) 

As  the  temperature  of  woman  is  a  little  inferior  to  that  of 
man,  the  result  obtained  by  Berger  is  in  accordance  with  mine. 

If  we  take  the  average  between  the  temperature  of  the  urine  of 


32 

man  as  I  have  found  it,  and  that  of  woman  as  Berger  has  found 
it,  we  have  a  number  very  near  102°  F.  (38°. 9  Cs.) 

From  these  facts  we  draw  the  conclusion  that  the  temperature  of 
the  thoracic  and  abdominal  viscera,  in  the  human  species  and  in 
both  sexes,  is  between  102  and  103°  F.  (38^.89  and  39°.44  Cs.), 
i.  e.,  some  degrees  higher  than  it  is  generally  admitted. 

XI. — ON  THE  INFLUENCE  EXERTED  UPON  THE  GENERAL  TEMPERA- 
TURE OF  THE  BODY  BY  A  CHANGE  IN  THE  TEMPERATURE  OF  ONE 
OF  THE  EXTREMITIES. 

The  following  sentence  is  given,  as  an  axiom,  by  Dr.  W.  F. 
Edwards  :  «  We  cannot  either  raise  or  lower  the  temperature  of 
any  one  part  of  the  body,  without  all  the  other  parts  of  the  frame 
being  affected  and  suffering  a  corresponding  rise  or  fall  in  tem- 
perature, more  or  less,  according  to  circumstances."* 

Expressed  in  such  terms,  we  accept  this  law  as  perfectly  true. 
But  the  author  elsewhere  gives  an  extension  to  this  law,  which 
we  will  prove  to  be  incorrect.  No  doubt  when  the  temperature 
of  the  blood,  coming  to  the  heart  from  a  remote  part  of  the 
body,  has  been  modified  in  that  part,  the  thoracic  viscera  ought 
to  have  their  temperature  modified  ;  but  to  what  extent  ?  It  is 
on  this  very  important  point  that  we  do  not  agree  with  Dr. 
Edwards.  He  was  of  opinion  that  the  influence  exerted  by  a 
small  part,  on  all  the  other  parts  of  the  body,  was  considerable. 
He  says  that  the  chilling  of  a  single  part,  such  as  the  hand  or 
the  foot,  may  cause  a  loss  of  temperature  in  all  the  other  parts 
of  the  frame,  even  far  beyond  what  could  have  been  presumed  as 
likely  or  possible,  and  that  in  a  number  of  experiments  where  one 
hand  was  plunged  in  water  cooled  down  by  ice,  the  other  hand, 
which  was  not  subjected  to  the  action  of  the  cold  bath,  lost 
nearly  5°  H.  (11°.25  F.,  6°.25  Cs.)  in  temperature. 

It  will  be  easily  understood  how  important  it  would  be  that 
practitioners  should  be  able  to  act  on  the  general  temperature  of 
a  patient,  so  as  to  increase  or  diminish  it,  by  means  of  a  hand  or 
a  foot  bath.  I  ,regret  to  say  that  if  the  facts  observed  by 
Edwards  are  exact,  his  conclusion  nevertheless  is  incorrect. 

*  Article  Ani?nal  Heat,  in  Todd's  Cyclop,  of  Anat.  and  Physiol.,  1839, 
t.  ii.,  p.  660. 


33 

I  have  performed,  both  alone,  and  with  the  help  of  Dr. 
Tholozan,  Physician  of  the  Hospital  Val-de-G-race  at  Paris, 
numerous  experiments,  with  the  view  of  knowing  whether  Dr. 
Edwards  was  right  or  not.  I  have  found  that  the  chilling  of 
one  hand  plunged  in  water  at  the  temperature  of  freezing  point, 
acted  very  strongly  on  the  temperature  of  the  other  hand.  But, 
at  first,  there  is  no  regularity  at  all  in  the  quantity  of  degrees 
of  temperature  lost  by  the  hand  which  remains  out  of  the  water; 
and  secondly,  ^ye  have  found  once  that  this  hand  did  not  lose 
any  fraction  of  its  temperature.  In  one  case  we  have  observed 
that  the  hand  kept  in  the  atmosphere  did  lose  22°  F.  (12°  Cs.) 
in  seven  minutes.  The  ordinary  loss  of  temperature  has  been  of 
between  6  to  8°  F.  (3.33  to  4°.44  Cs.)  In  one  case  there  has 
been  only  a  loss  of  2°  F.  (1°.2  Cs.)  In  another  case  there  has 
been  no  loss,  and,  on  the  contrary,  there  has  been  an  increase  of 
temperature  of  1°.4  F.  (0°.8  Cs.) 

If,  like  Edwards,  we  consider  the  loss  of  temperature  of  the 
hand  not  plunged  in  water  as  a  sign  and  as  a  measure  of  the 
diminution  of  the  general  temperature  of  the  body,  we  must 
conclude,  from  our  experiments,  that  the  chilling  of  a  small  part 
of  the  body  may  be  unable  to  diminish  the  temperature  of  the 
body  sensibly,  and  that,  in  other  cases,  it  may  act  extraordinarily 
upon  it.  But  the  supposition  that  the  hand  kept  in  the  atmos- 
phere, was  able  to  give  a  measure  of  the  modification  of  the  body 
is  incorrect.  By  taking  the  temperature  of  the  mouth  during  the 
time  that  one  hand  was  dipped  into  very  cold  water,  Dr.  Tholo- 
zan and  myself  have  ascertained  that  the  temperature  of  the 
body  does  not  sensibly  change.  The  greatest  diminution  of  the 
temperature  of  the  mouth  has  been  nearly  1°  F.  (Op.6  Cs.), 
and  this  only  in  one  case.  In  that  experiment  in  which  the 
hand  not  plunged  in  water  lost  22°  F.  (12°  Cs.),  the  tempe- 
rature of  the  mouth  was  not  diminished  more  than  the  fifth  of 
a  Fahr.  degree. 

As  it  is  quite  certain  that  the  temperature  of  the  body  is  con- 
stantly changing,  it  is  easy  to  understand  why  we  do  not  find  a 
small  but  a  constant  diminution  in  the  temperature  of  the 
mouth  when  one  hand  is  subjected  to  a  notable  chilling.  When, 
under  the  unknown  influences  that  are  constantly  modifying  the 
temperature  of  the  body,  there  is  a  tendency  to  increase  that 


34 

temperature,  then  the  tendency  to  its  diminution  originating 
from  the  chilling  of  one  hand  may  exist  without  producing  any 
effect.  We  have  there  two  causes  acting  in  opposite  directions, 
and  if  they  are  equal  they  annihilate  each  other.  If  they  are 
unequal,  we  perceive  only  the  difference  between  them.  When 
these  two  causes  act  in  the  same  direction,  then  their  efforts  are 
added  to  one  another,  and  it  is  probably  in  a  circumstance  of 
that  kind  that  I  have  once  found  a  diminution  of  1°  F.  (0.°56C,) 
taking  place  in  the  mouth. 

We  have  now  to  examine  how  the  diminution  of  the  temperature 
of  a  hand  is  produced  when  the  other  hand  is  dipped  into  cold 
water.  A  priori  it  is  evident  that  the  chilling  of  the  hand  kept 
in  the  air  exists  in  consequence,  either  of  the  arrival  of  a  cooler 
blood,  or  in  the  diminution  in  the  quantity  of  blood.  That  hand 
being  exposed  to  a  cold  air  (for  it  is  only  in  such  a  case  that  the 
experiments  succeed)  loses  its  temperature  by  the  action  of  that 
cold  air.  At  first  the  blood  that  arrives  in  the  hand  is  not 
cooler,  as  Edwards  had  supposed  it  was.  This  we  prove  by  the 
fact  that  the  temperature  is  but  very  little  changed  in  the  mouth. 
The  supposition  then  remains  that  the  quantity  of  blood  ar- 
riving in  the  hand  is  smaller  than  usual.  This  may  happen  by 
two  modes,  one  of  which  is  that  the  heart  sends  less  blood,  and 
the  other  that  the  blood-vessels  of  the  hand  are  contracted  and 
prevent,  in  part,  the  passage  of  blood.  It  is  certain  that  the 
heart  continues  perceptibly  to  send  the  same  quantity  of  blood. 
Therefore  we  are  induced  to  admit  that  the  hand's  blood-vessels 
are  contracted.  But  now  what  is  the  cause  of  that  contraction  ? 
We  will  try  to  show  that  it  is  in  an  action  of  the  nervous  sys- 
tem. Every  one  knows  that  under  the  influence  of  a  sensation 
or  of  emotion,  the  hands,  and  sometimes  the  feet,  become  cold. 
The  nervous  system,  in  consequence  of  that  sensation  or  emotion, 
acts  upon  the  blood-vessels  and  excites  them  to  contract.  The 
calibre  of  the  visible  vessels  is  sensibly  diminished.  The  same 
phenomena  take  place  in  the  two  hands  when  one  is  dipped  into 
very  cold  water.  An  exceedingly  violent  pain  is  felt,  the  nervous 
centres  are  strongly  excited,  and  they  act  then  as  under  the  in- 
fluence of  an  emotion.  Dr.  Tholozan  and  myself  have  observed 
that  the  greater  the  pain  felt,  the  more  the  temperature  was  di- 
minished in  the  hand  left  in  the  air. 


35  i 

.  As  to  the  influence  of  partial  heating  Dr.  Edwards  relates 
the  following  experiment : 

"  The  hand  being  immersed  in  water  heated  to  the  temperature 
of  34°  R.  (lOS^.SF — 42°.5Cs.)  rose  one  degree  of  the  same 
scale,  and  the  temperature  of  other  remote  parts  not  imme- 
diately exposed  to  the  influence  of  heat  were  found  to  have  risen 
to  a  corresponding  degree." 

I  have  repeated  this  experiment  of  Dr.  Edwards,  and  I  have 
found  no  evident  elevation  in  the  temperature  of  remote  parts,  as 
the  mouth  and  the  hand,  not  immersed  in  water. 

I  conclude,  then  from  the  facts  contained  in  this  note,  that,  in 
general,  the  temperature  of  the  body  is  not  sensibly  modified 
by  the  chilling  or  the  heating  of  a  small  part  of  the  frame. 

XII. — ACTION  OF  COLD  ON  THE  COAGULABILITY  0F  BLOOD,  AND 
PERSISTENCE  OF  LIFE  IN  FROGS  AFTER  LOSING  HALF  OF  THE 
VENTRICLE  OF  THE  HEART. 

Dr.  Marchal  (de  Calvi)  and  other  physiologists,  have  recently 
asserted  that  cold  diminishes  the  quantity  of  fibrine  and  conse- 
quently the  coagulability  of  blood.  I  have  observed  a  curious 
fact,  which  shows  that  blood  may  possess  a  very  great  coagula- 
bility although  exposed  to  the  action  of  cold.  I  have  found  that 
after  the  removal  of  the  half  of  a  ventricle,  in  frogs,  the 
blood  may  coagulate  at  the  surface  of  the  wound  and  the  ani- 
mal may  continue  to  live.  After  the  mutilation  has  been  made, 
the  lips  of  the  wound  are  drawn  upwards  and  inside  in  conse- 
quence of  the  muscular  contraction.  The  blood  flows  very 
abundantly,  but  its  coagulation  quickly  begins,  and  a  layer  of 
solidified  blood  is  soon  formed  on  the  entire  surface  of  the  sec- 
tion, and  by  this  process  the  wound  is  rapidly  obliterated.  The 
hemorrhage  has  been  frequently  stopped  in  a  few  minutes. 

This  experiment  is  successful  only  in  cold  seasons,  probably 
because  the  batrachia  are  able  to  bear  much  better  a  loss  of 
blood  at  a  low  than  at  a  high  temperature.  The  pulsations  of 
such  mutilated  hearts  continue  with  regularity  and  strength,  but 
the  impulse  given  by  the  remaining  of  the  ventricle  ought  to 
be  diminished.  Nevertheless  the  circulation  of  blood  is  accom- 
plished well  enough  to  allow  the  animal  to  live  many  months. 


36 

I  have  shown  to  the  Societe  de  Biologie  at  Paris,  two  frogs  on- 
which  the  wound  of  the  heart  was  cicatrised  after  fifteen  days.* 

XIII. — ON  A    SINGULAR   CASE   OF  ANIMAL    GRAFT. 

Every  one  knows  the  experiments  by  which  the  cock's  spurs 
or  many  other  animal  textures  have  been  grafted  on  the  body  of 
an  animal,  and  especially  on  a  cock's  comb.  I  have  succeeded 
in  grafting  the  tail  of  a  young  cat  on  a  cock's  comb.  I  per- 
formed this  experiment  in  France  in  1850. 

After  having  divided  the  tail  of  a  young  cat,  I  made  a  longi- 
tudinal section  on  a  cock's  comb,  and  I  united  these  two  parts 
one  to  the  other,  by  stitching  the  cut  surface  of  the  cat's  tail  to 
the  cut  surface  of  the  cock's  comb.  The  skin  of  the  cat's  tail 
had  been  turned  a  little  over  itself,  so  that  its  internal  surface 
was  in  contiguity  with  the  cut  surface  of  the  cock's  comb.  Eight 
days  after,  I  punctured  the  skin  of  the  tail  at  a  distance  from 
the  cock's  comb,  and  blood  escaped,  so  that  it  was  evident  that  cir- 
culation was  already  established.  The  tail  had  been  cold  during 
all  the  day  of  the  operation,  but  it  became  warmer  gradually 
from  the  second  day.  The  union  appeared  much  advanced  on 
the  third  or  fourth  day.  The  tail  was  entirely  fixed  on  the 
eighth  day. 

Unfortunately,  on  the  eleventh  day,  the  cock  had  a  fight  with 
another  cock,  and  the  cat's  tail  was  torn  out  from  the  ground 
on  which  it  had  been  fixed.  I  was  thus  deprived  of  the 
opportunity  of  knowing  what  transformations  should  have  taken 
place  in  the  tail. 

By  examining  it  I  found  that  all  its  tissues  were  fresh,  and 
that  its  blood-vessels  contained  blood. 

XIV. — ON  A  CONVULSIVE  AFFECTION  PRODUCED  BY  CONSIDERABLE 
INJURIES  OF  THE  SPINAL  CORD. 

I  have  discovered  that  a  very  violent  convulsive  affection  is 
the  constant  result  of  a  considerable  wound  of  the  spinal  cord, 
in  certain  animals.  It  is  more  especially  in  guinea-pigs  in  whom 
a  transversal  section  of  a  lateral  half,  or  a  complete  section  of 

*  See  Gaz.  Med.  de  Paris,  1850,  t.  v.  p.  169. 


37 

the  spinal  cord  has  been  made,  that  this  is  the  case.*  The  section 
was  made  at  the  level  of  one  of  the  last  six  dorsal  vertebrae  or 
the  two  first  lumbar. 

When  the  convulsive  fit  begins,  the  muscles  of  the  face  and 
neck  are  the  first  which  contract.  The  convulsions  occur  alter- 
nately in  all  the  muscles  of  the  eye,  the  face,  the  tongue,  the 
jaws  and  the  neck ;  so  that  the  cause  of  these  movements  ought 
to  act  on  the  parts  of  the  encephalon,  from  whence  the  facial, 
the  trigeminal,  the  hypoglossus,  and  the  motor  nerves  of  the 
eyes  originate.  The  head  of  the  animal  is  alternately  bent 
on  both  sides  of  the  body,  and  lastly  the  limbs  are  agitated 
in  every  direction.  In  the  case  of  a  section  of  the  lateral 
half  of  the  spinal  cord,  in  the  lumbar  region  or  at  the  end 
of  the  dorsal  region,  three  limbs  only  are  strongly  convulsed ; 
the  two  anterior  and  one  of  the  posterior — the  one  that  is  on 
the  side  of  the  body  opposite  to  the  side  of  the  section  of  the 
spinal  marrow.  The  other  posterior  limb  has  only  very  slight 
movements.  When  the  spinal  cord  has  been  entirely  divided  in 
the  dorsal  or  lumbar  regions,  the  two  anterior  limbs  only  are 
convulsed,  with  the  muscles  of  the  face  and  neck.  These  con- 
vulsions may  come  without  any  exterior  excitation ;  but  it  is  very 
easy  generally  to  provoke  them  by  frightening  the  animal,  or 
by  pinching,  burning  or  otherwise  exciting  it.  The  part  of  the 
body  upon  which  a  mechanical  excitation  acts  more  powerfully 
is  the  skin  of  the  face  or  the  neck.  This  convulsive  affection 
has  a  great  analogy  with  epilepsy ;  but  it  has  also  some  dis- 
tinctive features, — for  instance,  the  animals,  during  the  convul- 
sions, do  not  appear  to  lose  their  consciousness,  and  they 
frequently  cry  when  they  are  pinched. 

The  affection  begins  generally  eight,  ten  or  twelve  days 
after  the  spinal  cord  has  been  wounded.  The  convulsions  then 
are  not  very  strong,  and  it  is  usually  four  or  five  weeks  after 
the  operation  that  the  fits  are  violent  and  easily  produced. 
Three  or  four  months  after,  the  violence  and  frequency  of  these 
convulsions  are  diminished ;  yet  in  two  or  three  instances  they 
have  increased  in  strength  and  frequency  more  than  a  year  after 
the  operation.  The  affection  may  last  a  long  time:  in  one  case 
it  still  existed  two  years  after  the  operation. 

*  See  Gaz.  Med.  de  Paris,  1850,  t.  v.  pp.  651,  895. 
4 


38 

Generally  the  fits  last  from  five  to  fifteen  minutes.  The 
stronger  they  are  the  shorter  is  their  duration.  For  an  hour  or 
two,  and  sometimes  for  one  or  two  days  after  a  violent  fit,  it  is 
impossible  to  produce  another  one  by  any  kind  of  excitation. 
When  a  fit  takes  place  a  short  time  after  a  violent  one,  it  is 
always  weak  or  very  short. 

I  have  made  the  following  experiment  on  some  guinea-pigs 
having  this  convulsive  affection  :  I  put  them  in  a  small  box,  so 
that  they  had  but  little  room  to  move,  and  I  gave  them  food 
in  great  abundance.  They  then  ate  very  much  and  were 
deprived  of  exercise,  and,  in  consequence  of  that  mode  of  living, 
they  had  exceedingly  frequent  convulsions.  One  of  them  had 
a  fit  nearly  every  quarter  of  an  hour.  These  fits  sometimes  were 
strong,  but  they  did  not  last  long.  The  others  had  fits  three  or 
four  times  every  day.  I  changed  their  mode  of  living,  and 
put  them  all  in  a  large  room  where  they  had  only  a  small  quan- 
tity of  food.  The  influence  of  this  new  regimen  was  nearly 
immediate ;  the  same  day  the  number  of  fits  was  diminished, 
and  in  the  course  of  the  third  week  afterwards  they  had  only 
one  or  two  fits ;  and  before  long  some  of  them  were  cured. 

I  must  relate  also  a  very  interesting  fact  analogous  to  the 
preceding.  In  several  guinea-pigs  and  frogs,  which  had  the 
spinal  cord  transversely  divided,  I  have  observed  that  when  the 
animals  remained  very  quiet  during  many  days,  instead  of  the 
regular  reflex  movements,  they  had  a  violent  tetanic  convulsion 
in  their  posterior  limbs,  when  the  skin  of  these  limbs  was 
pinched. 

Such  a  tetanic  movement  never  occurred  in  these  animals 
when  I  excited  the  regular  reflex  movements  every  day. 

I  have  no  room  in  this  resume  to  try  to  explain  the  facts 
related ;  I  will  do  it  in  a  special  paper.  I  will  only  add  that  all 
the  readers  of  this  note,  who  know  the  views  of  Dr.  Marshall 
Hall  about  convulsive  diseases,  will  remark  how  strongly  the 
facts  I  have  pointed  out  are  confirmatory  of  these  views. 

XV ON  THE  RELATIONS   EXISTING  BETWEEN  THE  ORGANISATION 

OF   NERVE   TUBES   AND   THEIR  VITAL   PROPERTIES. 

It  is  well  known  that  when  the  nerve  tubes  are  examined  in  a 
very  fresh  state,  their  contents,  the  medulla^  or  white  substance  of 


39 

Seluvann,  appear  pellucid  and  homogeneous,  and  of  a  fluid  con- 
sistence ;  but  a  kind  of  coagulation  soon  takes  place  in  that  me- 
dulla, making  it  easily  distinguishable  from  the  tube  itself,  solid, 
grumous  and  much  less  transparent.  Water  has  the  power  of 
producing  very  quickly  that  kind  of  coagulation  of  the  white 
substance  of  Schwann,  and  the  more  quickly  the  warmer  it  is. 

It  was  interesting  to  ascertain  whether  a  nerve-fibre  keeps  or 
loses  its  vital  properties  when  its  contents  have  been  transformed 
by  coagulation.  I  have  performed  two  series  of  experiments  in 
order  to  solve  this  question ;  one  on  the  motor  nerves,  the  other 
on  the  nerves  of  sensibility. 

1st.  After  having  amputated  the  two  limbs  of  a  frog,  I  laid 
bare  a  long  portion  of  the  sciatic  nerve  in  both.  Half  an  hour 
afterwards  these  two  nerves  were  still  able  to  act  perfectly 
well.  Then  a  microscopical  examination  of  some  fibres  from 
one  of  these  nerves  demonstrated  that  the  coagulation  of  the 
medulla  had  begun,  but  was  not  yet  complete.  Ten  minutes 
later  the  nerves  were  still  capable  of  acting,  and  the  microscope 
showed  that  the  coagulation  was  complete.  A  similar  experi- 
ment repeated  a  great  many  times  has  always  furnished  the 
same  result. 

2d.  After  having  divided  the  two  sciatic  nerves,  not  far  from 
the  knee-joint,  in  a  living  frog,  I  have  dipped  the  central  part 
of  these  nerves  into  water.  After  a  few  minutes,  some  fibres 
taken  from  one  of  them  were  beginning  to  coagulate ;  yet  these 
nerves  possessed  their  sensibility.  Ten  minutes  after,  there  was  a 
complete  coagulation  of  the  medulla,  while  the  sensibility  was 
very  little  if  at  all  diminished. 

I  draw  from  these  facts  the  conclusion  that  nerve-fibres  are 
capable  of  acting  nearly  as  well  when  their  contents  are  coagu- 
lated, as  when  they  are  still  liquid. 

This  result  appears  to  be  important,  inasmuch  as  it  contri- 
butes to  show  that  the  white  substance  of  Schwann  has  not  a  great 
part  in  nervous  action.  Three  reasons  concur  in  demonstrating 
that  the  essential  part,  the  truly  active  one — that  which  pos- 
sesses the  vital  properties — is  not  the  white  substance  of 
Schwann : 

1.  We  see  that  the  vital  properties  of  the  nerve-fibres  do  not 


40 

appear  altered,  although  there  is  a  very  material  change  in  this 
substance  when  it  coagulates. 

2.  If  such  a  change  as  that  which  takes  place  in  this  sub- 
stance when  it  coagulates,  existed  in  a  part  possessing  the  vital 
properties  belonging    to    nerves,  there  should  certainly  be  a 
movement  or  a  sensation  accompanying  it,  and  yet  there  is  none. 
This  material  change  is  certainly  more  considerable  than  the 
change  effected  by  a  slight  mechanical  or  galvanic  excitation, 
which  is  capable  of  producing  a  movement  or  a  sensation. 

3.  The  microscope  has  already  proved  that  the  white  sub- 
stance does  not  exist  in  all  the  nerve-fibres,  and  that  it  is  want- 
ing, for  instance,  in  the  very  fine  fibres. 

Therefore  if  it  be  not  the  white  substance  of  Schwann  which 
is  active  in  the  nerves,  and  as  it  is  not  the  cylinder  axis  which 
possesses  the  vital  properties  of  the  nerves,  because  it  is  wanting 
in  many  fibres,  it  results  that  it  is  the  membranous  layer,  the 
paries  of  the  nerve-tube,  to  which  these  vital  properties  belong, 
unless  there  is  another  substance,  still  unknown,  and  existing  in 
the  tubular  canal  of  the  nerve-fibre. 

XVI ON  THE  PERSISTENCE  OF   LIFE   IN   ANIMALS    DEPRIVED  OF 

THEIR  MEDULLA   OBLONGATA.* 

I.  There  is  no  part  in  the  nervous  system  considered  as  more 
essential  to  life  than  the  medulla  oblongata.  In  the  last  few  years 
many  German  physiologists  have  asserted  that  this  nervous 
centre  is  the  source  of  the  rhythmical  movements  of  the  heart. 
Besides,  an  eminent  physiologist  maintains  that  in  the  medulla 
oblongata  a  small  part  exists  which  is  the  focus  of  vital  power. 
Moreover,  it  is  certain  that  the  medulla  oblongata  has  a  great 
share  in  the  respiratory  movements.  Therefore  it  seemed  pro- 
bable that  the  ablation  of  such  an  organ,  even  in  cold-blooded 
animals,  ought  to  be  speedily  followed  by  death.  Such  is  not, 
however,  the  result  of  that  operation ;  and  in  favorable  condi- 
tions, the  batrachia,  for  instance,  can  live  more  than  four 
months  after  the  loss  of  the  medulla  oblongata.  During  all  that 
time,  these  animals,  in  appearance  remain  in  good  health,  and  I 
have  observed  in  them  the  existence  of  all  the  following  func- 
tions and  properties : 

*  See  the  Bulletin  de  la  Soc.  Philomatique.    Paris,  1849,  p.  117. 


41 

1.  The   circulation    of  blood   continues  as   well   as    in    un- 
mutilated  frogs.     The  beatings  of  the  heart  are  at  -first  quick- 
ened generally  during  half  an  hour,  an  hour  or  an  hour  and  a 
half,  after  the  operation;    they  then  return  to  their   normal 
rhythm,  and  they  are  found  as  regular  and  vigorous  in  frogs  de- 
prived of  their   medulla   oblongata,  for   several  days  or  even 
several  months,  as  in  healthy  frogs.     Sometimes,  particularly 
when  the  hemorrhage  has  been  considerable,  the  beatings  of  the 
heart  become  less  numerous  and  less  energetic ;  then  the  animal 
dies  very  quickly,  but  if  it  lives,  the  movements  of  the  heart  re- 
suiae  before  long  their  normal  rhythm  and  strength. 

2.  The  pulsations  of  the  four  lymphatic  hearts  take  place  as  in 
healthy  frogs. 

8.  Digestion  seems  to  be  carried  on  as  well  and  as  quickly  in 
frogs  without  medulla  oblongata  as  in  healthy  frogs.  I  have 
ascertained  this  fact  by  introducing  pieces  of  earth-worms  into 
the  stomach  of  these  animals,  and  by  studying  the  changes  pro- 
duced in  these  aliments  during  their  passage  along  the  digestive 
canal.  Although  very  slow,  chymous  transformation,  absorp- 
tion and  the  production  of  faeces  took  place. 

4.  The  products  of  the  gastric,  intestinal,  biliary  and  pan- 
creatic secretions  being  very  useful,  if  not  essential  to  digestion, 
it  is  very  probable  that  these  secretions  exist. 

5.  The  urinary  secretion  and  also  the  production  of  cutaneous 
and  intestinal  epithelium,  are  performed  as  usual. 

6.  The  pulmonary  respiration  ceases,  but  the  cutaneous  respi- 
ration is  continued.     The  absorption  of  poisons  by  the  skin  and 
by  the  mucous  membranes  exists  as  in  healthy  frogs. 

7.  The  reflex  faculty  is  energetic,  and  so  much  so  that  the 
frogs  deprived  of  the  medulla  oblongata  can  raise  by  a  reflex 
action,  greater  weights  than  healthy  frogs.   As  reflex  movements 
exist,   I   need   not   say   that   muscles   and    nerves  have   kept 
their  vital  properties.     It  is  frequently  found  that  the  spinal 
cord,  especially  in  the  rana  temporaries,  becomes  so  excitable 
that  the  slightest  irritation  of  the  skin  is  followed  by  tetanic 
convulsions. 

8.  The  galvanic  current   of  muscles  not  only  exists  in  frogs 
deprived  of  medulla  oblongata,  but  appears  to  be  stronger. 

From  these  facts  it   results  clearly  that  frogs,  deprived  of 


42 


their  medulla  oblongata,  are  in  full  life.  It  is  so  much  so  that 
if  they  are  compared  to  frogs  possessing  that  nervous  centre, 
they  resist  etherisation  longer,  and  also  live  longer  after  the 
ablation  of  the  heart. 

II.  The  greatest  differences  exist  in  the  duration  of  life,  after 
the  removal  of  the  medulla  oblongata,  in  animals  of  different 
species,  as  will  be  seen  in  the  following  table,  where  the  maxi- 
mum duration  of  life  is  indicated  in  sixty  different  species  of 
animals : 

Classes.  Species. 

f  Salamanders 

Amphibia.    )  Frogs    ..... 
(  Toads    . 


Duration  of  life. 
More  than  4  months. 
4  to  5  weeks. 


Reptilia. 


Fishes. 


Birds. 


Tortoises         .          .          .          .  9  to  10  days. 

Snakes  .          ,          .          .  6  to  7  days. 

Lizards  .          .          .          .  4  to  6  days. 

Eel 6  days. 

Pike,  carp,  tench,  eel  pout,  barbel  3  days. 

Perch,  gudgeon  and  others          .  25  to  40  hours. 

Sparrowhawk  (newly  born)         .  21  minutes. 

Magpie  do.  .  19  minutes. 

Sparrow  do.  .  17  minutes. 

Sparrow,  yellowhammer,  linnet,  pi- 
geon, fowl,  duck,  pintaw,  par- 

tridge,'moor-hen,  turtle-dove  (adult)  2|  to  3  minutes. 


29  hours. 
23  hours. 
46  minutes. 
41  minutes. 
34  minutes. 
6  minutes. 


4  minutes. 


c  Dormouse  (during  hybernation) 
Hedgehog  ditto 

Bull-dog  (newly  born) 
Cat  ditto 

Mammals.*  j  Rabbit  ditto 
Guinea-pig  ditto 
Dormouse  and  Hedgehog  awaken  in 

summer     .... 
Cat,  rabbit,guinea-pig  and  dog  (adult)  3  to  3|  minutes. 

The  preceding  table  shows  that  after  the  removal  of  the  me- 
dulla oblongata,  in  different  species  of  animals,  the  duration  of 
life  may  be  reckoned  by  months  for  batrachia,  by  weeks  for  some 
reptilia,  by  days  for  other  reptilia  and  for  fishes,  by  hours  for 

*  Pulmonary  insufflation  has  been  used  only  for  the  dormouse  and 
hedgehog  during  hybernation. 


43 

hybernating  mammals,  and  by  minutes  for  birds  and  non-hyber- 
nating  mammals. 

III.  After  the  removal  of  the  medulla  oblongata,  the  most 
remarkable  differences  in  the  duration  of  life,  in  different  indi- 
viduals belonging  to  the  same  species,  may  occur  in  consequence 
of  differences  of  temperature.     The  lower  the  temperature  the 
longer  is  the  duration   of  life.     Thus,  the  duration  of  life  in 
frogs  may  be  reckoned  by  months  when  the  temperature  is  be- 
tween 32°  and  46°  F.,  (0  and  8°  Cs.) ;  by  weeks  when  it    is 
between  40°  and  55°  F.  (5°  and  13°  Cs.) ;  by  days  when  it  is 
between  50°  and  65^>  F.  (10°  and  18°  Cs. )  by  hours  when  it  is 
between  65°  and  72°  F.  (18°  and  24*  Cs.) ;  and  by  minutes  when 
it  is  between  86°  and  105^  F.  (30°  and  40°  Cs.) 

In  the  other  cold-blooded  vertebrata  the  differences  in  the 
duration  of  life,  after  the  removal  of  the  medulla  oblongata,  are 
not  so  great  as  in  frogs,  but  the  law  is  the  same.  This  law 
exists  also  for  warm-blooded  animals,  so  much  so  that  the  differ- 
ences existing  between  mammals  of  different  ages  and  of  differ- 
ent species,  are  to  be  attributed,  in  part,  to  their  differences  of 
temperature. 

IV.  As  the  principal  condition  for  a  long  duration  of  life 
in   cold-blooded   vertebrata   is   a   cold  atmosphere,  and  as  the 
vital  phenomena  taking  place  in  these  animals  are  much  dimi- 
nished when  they  are  exposed  to  a  low  temperature,  some  phy- 
siologists have  supposed  that  the  persistence  of  life  for  many 
weeks  or  more,  was  equivalent,  as  regards  the  sum  of  the  vital 
phenomena,  to  a  duration  of  some  hours  in  summer,  when  these 
phenomena  have  a  great  activity. 

In  answer  to  this  objection  I  will  at  first  call  the  reader's 
attention  to  the  fact  that,  in  batrachia,  deprived  of  the  medulla 
oblongata,  and  exposed  to  the  action  of  a  low  temperature,  the 
heart  beating,  on  an  average,  35  times  in  a  minute  and  life 
lasting  four  months — i.  e.  172,800  minutes,  it  follows  that,  during 
that  time,  the  heart  has  more  than  6,000,000  pulsations.  In 
summer,  the  maximum  duration  of  life  having  been  six  hours — 
i.  e.  360  minutes,  and  the  heart  beating,  on  an  average,  45  times 
in  a  minute,  it  results  that,  during  that  life,  the  heart  has  only 
1,600  pulsations — a  number  which  is  to  the  other  as  1  is  to  375. 


44 

This  comparison  shows  how  incorrect  it  is  to  suppose  that  in 
consequence  of  the  diminution  of  the  vital  phenomena  in  cold  wea- 
ther, a  batrachian  that  lives  several  months  does  not  live  more 
than  another  living  only  several  hours  in  summer. 

This  opinion  is  also  proved  erroneous  by  the  facts  which  I  have 
already  related,  and  which  show  that  all  the  functions  and  vital 
properties  existing  in  frogs  deprived  of  their  medulla  oblongata, 
appear  to  be  as  active  as  in  unmutilated  frogs.  No  doubt  that 
there  is  a  notable  difference  between  summer  and  winter  as  to  the 
activity  of  vital  phenomena  in  frogs,  but  if  we  suppose  that  these 
phenomena  are  in  winter  only  the  tenth  of  what  they  are  in 
summer,  and  if  we  consider,  consequently,  the  duration  of  life  in 
winter  as  being  only  the  tenth  of  what  it  is,  we  shall  have, 
nevertheless,  a  duration  in  winter  forty  or  fifty  times  as  great  as 
the  duration  in  summer. 

V.  Now  I  have  to  examine  why,  in  summer,  the  life  of  cold- 
blooded vertebrata,  deprived  of  the  medulla  oblongata,  is  much 
shorter  than  in  winter. 

The  principal  cause  of  this  difference  is  in  the  fact  that  the 
cutaneous  respiration,  (it  is  known  that  the  pulmonary  respira- 
tion does  not  exist  in  animals  deprived  of  the  medulla  oblon- 
gata,) which  is  sufficient  as  long  as  the  temperature  is  very  low, 
becomes  more  and  more  insufficient,  when  the  temperature  be- 
comes more  and  more  elevated.  So  that  the  same  law  exists  for 
the  cold-blooded  vertebrata  deprived  of  their  medulla  oblongata, 
and  for  those  which  are  not  mutilated.  The  following  experi- 
ments concur  to  demonstrate  the  correctness  of  this  view : 

I  have  found  that  frogs  deprived  of  their  medulla  oblongata 
live  much  longer  when  placed  in  oxygen  than  in  atmospheric  air. 
I  have  made  two  series  of  experiments — one  in  June,  1847,  the 
other  in  July,  1850.  In  both  series  the  frogs  were  put  imme- 
diately after  the  operation,  under  a  receiver  full  of  oxygen.  They 
lived  from  eight  to  fourteen  days  at  a  temperature  at  which 
life,  in  atmospheric  air,  is  always  shorter  than  six  hours.  The 
temperature  was  from  64*  to  84°  F.  (18°  to  29°  Cs.)  These 
frogs  would  have  lived  longer  if  the  quantity  of  oxygen  had 
been  more  considerable. 

By  pulmonary  insufflation  I  have  maintained  life  in  tortoises 
deprived  of  the  medulla  oblongata,  much  longer  than  when  in- 


45 

sufflation  is  not  used.  The  duration  of  life  was  7,  12,  13 
and  17  days  in  four  insufflated  tortoises.  When  death  occurred 
in  these  four  animals,  they  had  been  left  without  insufflation 
more  than  five  or  six  hours,  and  very  likely  they  would  have 
lived  longer  had  they  been  insufflated  more  frequently.  In 
four  non-insufflated  tortoises  life  lasted  3,  7,  19  and  23  hours. 
These  comparative  experiments  were  made  in  summer  in  a  tem- 
perature varying  from  64°  to  86°  F.  (18°  to  30°  Cs.)  The  in- 
sufflated tortoises  lived  longer  in  summer  than  non-insufflated 
tortoises  in  winter. 

From  all  these  facts  it  is  evident  that  in  animals  deprived  of 
the  medulla  oblongata,  death  is  principally  caused  by  insuffi- 
ciency of  respiration. 

XVII ON  THE  INFLUENCE  OF  THE  TEMPERATURE  OF  A  WARM- 
BLOODED ANIMAL  UPON  THE  DURATION  OF  ITS  LIFE  WHEN  IT 
IS  ASPHYXIATED. 

One  of  the  most  positive  facts  in  physiology  is  that  every 
animal  needs  oxygen  in  order  to  live.  But  if  there  is  a  com- 
plete uniformity  as  to  the  necessity  of  oxygen  for  all  animals, 
there  is  also  the  greatest  variety  between  the  different  species  as 
to  the  quantity  of  that  gas  which  is  necessary  for  the  mainte- 
ance  of  life.  Very  probably  a  great  part  of  the  physiological 
differences  between  different  animals,  comes  from  the  difference 
in  the  quantity  of  oxygen  absorbed  by  their  blood  in  a  given 
time.  The  most  important  cause  of  the  differences  existing  be- 
tween cold  and  warm-blooded  animals,  and  between  young  and 
adult  animals,  is  to  be  found  in  the  differences  in  the  quantity 
of  oxygen  they  absorb. 

It  is  very  remarkable  that  one  of  the  principal  laws  relative 
to  the  anatomical  differences  existing  between  the  different  spe- 
cies of  animals,  appears  to  be  also  a  law  regulating  their  phy- 
siological differences.  In  an  anatomical  point  of  view,  a  mam- 
mal, at  the  different  periods  of  its  development,  presents 
alternately  the  forms  of  many  different  beings.  In  a  physiolo- 
gical point  of  view,  a  corresponding  transformation  occurs  for 
the  mammals.  They  exhibit  alternately  the  same  phenomena 
of  life  exhibited  by  many  other  different  animals.  For  instance, 
before  its  birth,  the  mode  of  breathing  of  a  mammal  is  the 


46 

same  as  that  of  fishes.  The  oxygen  absorbed  by  fishes  exists 
in  a  liquid  ;  the  oxygen  absorbed  by  the  mammal  foetus  exists 
also  in  a  liquid,  which  is  the  blood  of  the  mother.  In  fishes 
and  also  in  mammal  foetuses,  oxygen  has  to  pass  through  many 
membranes :  in  fishes,  through  the  mucous  membrane  of  the 
bronchia  and  the  membrane  of  the  capillary  vessels';  in  the 
mammal  foetuses,  through  the  membranes  of  the  capillary  vessels 
of  the  maternal  and  the  foetal  placentas,  and  their  mucous 
coverings.  After  birth  young  mammals  have  an  insufficient 
power  of  breathing,  and  in  this  they  are  like  the  reptilia.  They 
are  unable  to  absorb  a  sufficient  quantity  of  oxygen  to  resist 
the  influence  of  cold ;  and  their  power  of  retaining  life  when 
deprived  of  oxygen,  is  comparable  to  that  of  the  reptilia. 

This  fact  -has  been  well  established  by  the  experiments  of 
Buffon,  Boyle,  Ens,  Roose,  Haller,  Fontana,  Legallois,  and 
more  particularly  W.  F.  Edwards.  Nevertheless,  these  eminent 
experimenters  have  left  many  important  questions  without  so- 
lution, some  of  which  I  will  examine  here. 

In  order  to  study  the  influence  of  temperature  on  the  duration 
of  life  in  asphyxiated  animals,  W.  F,  Edwards  dipped  into 
water,  at  different  degrees  of  temperature,  many  animals  of 
different  ages.  Unhappily  he  did  not  take  notice  of  the  tem- 
perature of  the  animals  on  which  he  experimented ;  and  we 
will  show  that  this  circumstance  is  very  important,  because  the 
degree  of  that  temperature  at  the  instant  when  asphyxia  begins, 
has  a  considerable  influence  on  the  duration  of  life.  Conse- 
quently, to  discover  with  exactitude  the  influence  of  the  tempera- 
ture of  a  medium,  on  animals  deprived  of  breathing,  it  was 
necessary  to  operate  on  animals  at  the  same  temperature.  This 
has  been  done  neither  by  Edwards  nor  by  any  other  physiologist. 

A.  priori  it  is  easy  to  acknowledge  that  the  duration  of  life 
in  animals  asphyxiated  can  be  influenced  by  four  capital  circum- 
stances :  1st.  The  degree  of  the  temperature  of  the  animals ; 
2d.  The  degree  of  the  temperature  of  the  medium ;  3d.  The 
age  of  the  animals ;  4th.  Their  species. 

Consequently  four  series  of  experiments  were  to  be  performed. 
I  have  made  them,  and  I  propose  to  give  here  some  of  the  results 
I  have  obtained.  The  remaining  shall  be  detailed  in  a  special 
paper. 


47 

I.  Influence  of  the  Temperature  of  young  warm-blooded  animals 

on  the  length  of  their  resistance  to  Asphyxia. 
Experiment  1.  Nine  rabbits  of  the  same  brood  and  aged 
about  two  days,  were  dipped  into  water  at  25°  Cent.  (77°  Fahr.) 
Two  of  these  animals,  No.  1  and  No.  2,  had  the  temperature 
which  they  generally  have  when  they  are  in  their  nest  covered 
by  their  mother.  The  others  had  been  cooled  by  having  been 
exposed  to  the  action  of  an  atmosphere  at  10°  Cent.  (50°  Fahr.) 
No.  3  and  No.  4  had  been  exposed  for  a  quarter  of  an  hour ; 
No.  5  and  No.  6  for  three  quarters  of  an  hour ;  and  No.  7,  No. 
8  and  No.  9  for  an  hour  and  a  half.  The  results  are  represented 
in  the  following  table  : 

TABLE   I.* 

Mean 
Nos.  Temperature  of  Animals.  Duration  of  Life-  Duration  of  Life- 

1,  35°  to  36°  Cent.  (95  to  97°  Fahr.)  10'  1 

2,  ditto  ditto  14'   j 

3,  29°  to  30°  Cent.  (84°  to  86°  Fahr.  16'  1 

4,  ditto  ditto  21'  j 

5,  23°  to  24°  Cent.  (74°  to  75°  Fahr.)  20'  1 

6,  ditto  ditto  j 

7,  18°  to  19°  Cent.  (65°  to  66°  Fahr.)  22'  ^) 

8,  ditto  ditto  29'  I  28' 

9,  ditto  ditto  33'  j 

The  one  that  lived  shortest  (10',)  was  nearly  at  36°  Cent. 
(97°  Fahr. ;)  the  one  that  lived  the  longest  (33',)  was  nearly  at 
18°  Cent.  (65°  Fahr.)  The  difference  of  temperature  being 
17°  or  18°  Cent,  (about  32°  Fahr.)  the  difference  as  to  the 
duration  of  life  was  23  minutes — that  is,  nearly  two  minutes 
for  each  diminution  of  three  degrees  Fahr. 

The  same  experiment  performed  on  many  breeds  of  rabbits, 
has  always  given  very  nearly  the  same  results. 

These  experiments  prove  that  the  temperature  of  young  rab- 
bits has  a  decided  influence  upon  the  duration  of  their  life, 
when  they  are  deprived  of  breathing.  I  have  ascertained  that 
the  same  thing  takes  place  in  cats,  dogs,  mice,  and  many  species 
of  birds. 

Experiment  2.  I  dipped  into  water  at  the  temperature  of  25° 
Cent.  (77°  Fahr.)  three  bull-dogs. 

*  The  existence  of  reflex  movements  has  been  used  in  this  experiment 
and  in  all  the  others  as  the  proof  of  life. 


48 

TABLE    II. 
NOB.  Temperature  of  Animals.  Duration  of  Life. 

1,  .    38°  Cent,  (about  101°  Fahr.)     .    15' 

2,  .    30    "        86    "      .    24' 

3,  .    22    "        77    "      .    47' 

Between  No.  1  and  No.  3  the  difference  of  temperature  was 
16°  Cent.  (29°  Fahr. ;)  the  difference  in  the  duration  of  life  was 
thirty-two  minutes — that  is,  two  minutes  for  each  diminution  of 
one  centigrade  degree  (nearly  2°  Fahr.) 

Experiment  3.  I  put  a  ligature  around  the  trachea  of  four 
cur-dogs  of  the  same  brood,  and  aged  three  days. 

TABLE   III. 
Nos.  Temperature  of  Animals.  Duration  of  Life. 

1,  .  37°  Cent,  (about  999  Fahr.)  ,  13' 

2,  .  28    "       83    "  .  19' 

3,  .  24    "       76    "  .  31' 

4,  .  19    "       67    t:  .  51' 

So  that  between  the  two  extremes  the  difference  as  the  dura- 
tion of  life,  was  38  for  18  Cent,  (about  32°  Fahr.) 

Many  other  experiments  on  very  young  dogs  gave  very  nearly 
the  same  results. 

Experiment  4.  On  five  cats,  of  the  same  brood,  and  aged  two 
days,  I  put  a  ligature  around  the  trachea,  after  having  cooled 
three  of  them. 

TABLE   IV. 

Temperature  of  the  animals.  Duration  Mean 

NOB.  of  life.  duration. 

1,  36°  Cents.,  (about  97°  Fahr.)  21'  \  , 

2,  36        «          «      97      «  30   f 

3,  23  to  24  Cent.,  (74  to  76  Fahr.)  47   1  '' 

4,  22   to  23  Cent.,  (72  to  75  Fahr.)  50   j  2       , 

5,  17   Cent.,  (about  63  Fahr.)  53 
The  temperature  of  the  air  air  was  then  at  18 1°  Cents.,  (65  Fahr.) 

Experiment  5.  On  four  mice,  probably  aged  from  three  to 
eight  days,  I  put  a  ligature  around  the  trachea  after  having 
cooled  three  of  them. 

TABLE  V. 

NOB.  Temperature  of  the  animals.  Duration  of  life. 

1,  34°  Cents.,  (about  94°  Fahr.)  11' 

2,  27    "     «   81   «  '  14 

3,  22   «    "   72   «  10 

4,  18   "    «   65   «  14 

I  have  obtained  analogous  results  in  experimenting  on  birds. 


49 


Experiment  6.  On  seven  magpies,  aged  from  four  to  eight 
days,  I  put  a  ligature  around  the  trachea,  and  opened  widely 
the  thoraco-abdominal  cavity. 


Nos. 
1, 

2. 
3, 
4, 

5, 
6, 
7, 
8, 
9, 
10, 

11, 


TABLE    IV. 
Temperature  of  the  animals. 

36°  Cent.,  (about  97°  Fahr. 


36 
32 
31* 

26 
26 

22 
20 
20 
18 
10 


97 
97 
90 
79 

79 
72 
68 
68 
65 
65 


Duration 
of  life. 


20'  £ 

28  $ 


26 
39 
12 

58 

65 

87 

82 

103 


Mean 
duration. 

24  ' 


50 

72 
76 

92 


Experiment  7.  On  other  magpies  I  made  the  same  experi- 
ment, but  without  opening  the  thoraco-abdominal  cavity,  so  that 
asphyxia  was  much  more  complete. 

TABLE   VII. 
Nos.  Temperature  of  the  animals.  Duration  of  life. 

1,  35°  Cent.,  (95°  Fahr.)  8' 

2,  30        «        86      «  15 

3,  24        «        76      «  27 

4,  19        «        67      «  39 

I  have  obtained  nearly  the  same  results  from  experiments 
upon  many  sparrow-hawks,  ravens  and  jays. 

All  these  facts  show  how  considerable  is  the  influence  of  the 
temperature  of  certain  young  animals  and  birds  on  the  duration 
of  their  life  when  they  are  asphyxiated. 

II.  Differences  in  the  length  of  the  resistance  to   asphyxia  ac- 
cording to  the  species  of  animals. 

In  order  to  discover  what  is  the  influence  of  the  species,  I  made 
the  following  experiment.  I  tied  the  trachea  on  twenty-two  ani- 
mals belonging  to  eleven  species,  all  of  which  were  aged  about 
four  or  five  days.  Their  temperature  had  been  cooled  and  they 
were  all  at  about  26°  Cent.,  (79°  Fahr.)  The  temperature  of 
the  air  was  19°  Cent.  (67°  Fahr.) 

5 


Nos. 
1, 

2, 

3, 

4, 

5, 

6, 

7, 

8, 

9, 
10, 
11, 
12, 
13, 
14, 
15, 
16, 
IT, 
18, 
19, 
20, 
21, 
22, 


50 

TABLE   VIII. 

Species.                          Duration  of  life. 

Rabbit      .          .          18') 
do.         .          :          24  $      ' 
Guinea  pig          ,            6  ) 
do.              .            9   (      ' 

Mouse 
do. 
Dog 
do. 
Cat 

.          20  f 

.    27  ;  • 

.          25  > 
39  5 
31  £ 

do. 

36  5      * 

Sparrow 
do. 

8  £ 
12  5      ' 

Pigeon 
do. 

5  } 
9  S      ' 

Jay 
do. 

13  £ 
17  5      ' 

Raven 

14  > 

do. 

23  $      ' 

Sparrow  Hawks            16  ) 
do.            .          24  £      * 

Mag-pie               .          18  } 
do.         .                    25  S      ' 

Mean  duration  of  life. 

21' 


32 


10 


15 


20 


22$ 


Now  if  we  compare  birds  to  mammals,  we  see  that  generally 
mammals  resist  asphyxia  more  than  birds.  The  two  following 
tables  show  the  difference  : 


TABLE    IX. 
Mammals. 


Guinea-pigs    . 
Rabbits 

Mice 


Cats 


III. 


Average 


7*' 

21 

23£ 
32 
334 


TABLE    X. 
Birds. 

Pigeons 

Sparrows  .  ,.         !,. 

Jays 

Raven 

Sparrow  Hawks     . 

Mag-pies      ;  / 


Average 


7' 

10 

15 

18| 

20 

— 
15-J 


Influence  of  the  temperature  of  adult  warm-blooded  animals 
on  the  duration  of  life  when  they  are  asphyxiated. 

I  have  discovered  that  the  degree  of  the  temperature  of  adult 
non-hybernating  vertebrata  has  also  a  great  influence  on  their 


51 

power  of  resisting  asphyxia.  Dogs,  cats,  rabbits,  guinea-pigs 
and  birds,  are  subject  to  the  same  law  when  they  are  adult  as 
when  they  are  very  young.  The  lower  their  temperature,  the 
longer  they  live  when  they  are  asphyxiated.  But  although  the 
existence  of  this  law  for  adult  vertebrata  is  beyond  all  doubt,  it 
is  sometimes  very  difficult  to  ascertain  that  existence.  It  is  not 
easy  to  diminish  the  temperature  of  a  non-hybernating  adult 
mammal,  or  that  of  a  bird,  without  exhausting  the  nervous  and 
the  muscular  power  of  the  animal,  and  also  without  producing  a 
general  and  considerable  perturbation.  The  action  of  a  cold 
bath,  for  instance,  so  powerfully  excites  the  vertebrata,  that 
sometimes  violent  convulsions  take  place,  and  then  death  may 
occur  in  a  short  time,  even  before  the  animal  has  lost  10°  cent. 
(18°  Fahr.)  of  its  temperature.  However,  some  individuals  may 
be  cooled  without  being  exhausted  by  convulsions.  I  have  ex- 
perimented on  a  great  many  which  were  in  this  condition. 
For  more  than  eight  years,  without  intending  to  make  experi- 
ments on  this  subject,  I  have  had  the  opportunity  of  stating,  on 
more  than  a  hundred  adult  rabbits  or  guinea-pigs,  used  for  other 
researches,  that,  when  their  temperature  is  diminished,  the  dura- 
tion of  their  life,  when  they  are  completely  deprived  of  breathing, 
is  decidedly  longer  than  in  the  normal  state.  Whatever  has  been 
the  cause  of  the  cooling,  the  effect  has  been  the  same.  In  these 
numerous  experiments,  the  animal  heat  has  been  diminished, 
either  by  a  disease,  by  a  poison,  by  an  injury  in  the  nervous 
centres,  by  the  immersion  of  the  animal  in  melted  ice,  or  by  the 
application  of  a  layer  of  oil,  essence,  or  gelatine,  to  the  whole 
skin  of  the  animal. 

The  best  mode  of  cooling  a  non-hybernating  warm-blooded 
animal  is  to  make  the  following  experiment,  in  a  room  where  the 
temperature  of  the  air  is  not  far  from  freezing  point.  I  remove 
the  superior  part  of  the  cranium  of  a  mammal  or  of  a  bird,  and 
afterwards  cut  the  brain,  slice  by  slice,  from  the  anterior  to  the 
posterior  extremity.  After  the  ablation  of  the  cerebrum  and  the 
cerebellum,  the  animal  is  put  on  the  floor,  where  it  is  left  per- 
fectly quiet  for  an  hour  or  two.  If  the  experiment  is  made  on 
a  rabbit  or  a  guinea-pig,  the  temperature  of  the  animal  then  falls 
from  40°  Cent.  (104°  Fahr.)  to  30°  or  35°  Cent.  (86  or  95°  F.) 


52 

A  ligature  being  put  around  the  trachea,  I  find  that  the  animal 
is  then  able  to  live  generally  from  six  to  8  or  12  minutes. 

The  more  the  animal  heat  is  diminished,  the  more,  in  general, 
is  the  resistance  to  asphyxia^  except  in  cases  where  cooling  has 
been  produced  too  quickly. 

On  four  adult  rabbits,  I  put  a  ligature  around  the  trachea, 
and  have  obtained  the  following  results  : 

TABLE  XI.     ^ 
NOB.  Temperature  of  the  animals.  Duration  of  life. 

1,  391°  Cents.,  (103°  Fahr.)  3£' 

2,  35     «    95   «  6 

3,  30|  (between  86  and  87  Fahr.)  10 

4,  25  Cents.,  (77  Fahr.)  14 

On  three  guinea-pigs  I  put  a  ligature  around  the  trachea,  and 
found  the  following  facts : 

TABLE    XII. 
NOB.  Temperature  of  the  animals.  Duration  of  life. 

1,  40°  Cents.,  (104°  Fahr.)  2f ' 

2,  35        «       '95        «  5| 

3,  30        «          86       «  12 

The  longest  persistence  of  life,  after  the  cessation  of  breathing 
which  I  have  found  in  adult  non-hybernating  animals,  has  been 
in  a  cat  aged  five  months,  and  whose  temperature  had  been  di- 
minished to  19°  Cent,  (about  67°  Fahr.)  in  consequence  of  the 
laying  bare  of  the  abdominal  viscera,  and  of  the  ablation  of  the 
cerebrum  by  small  parts. 

I  will  say  only  a  few  words  about  my  experiments  on  adult 
birds. 

Two  pigeons  were  dipped  into  melting  ice.  In  one  of  them, 
whose  temperature  had  fallen  from  42°  Cent.  (108°  Fahr.)  to 
35°  Cent.  (95°  Fahr.)  life  lasted  six  minutes  after  the  ligature  of 
the  trachea.  In  the  other,  life  lasted  nine  minutes ;  its  tempe- 
rature had  fallen  from  42°  Cent.  (108°  Fahr.)  to  30°  Cent. 
(86°  Fahr.) 

I  have  obtained  nearly  the  same  results  in  experimenting  on 
fowls  and  on  ducks. 

Physicians  are  generally  astonished  at  seeing  that  men  at- 
tacked with  cholera  are  able  to  live  almost  without  breathing. 
My  experiments  show  that  the  principal,  if  not  the  only  cause 


53 

of  the  power  living  with  so  deficient  a  respiration,  is  the  diminu- 
tion of  temperature.  The  same  thing  occurs  in  the  last  hour  of 
life  in  many  cases  of  diseases,  and  particularly  those  of  the 
brain,  of  the  respiratory  organs,  and  in  that  dreadful  disease  of 
children  called  scleroma. 

It  is  easy  to  understand  how  a  considerable  breathing  becomes 
less  and  less  necessary  when  the  temperature  of  the  animals 
under  experiment  is  diminishing. 

Whatever  may  be  the  function  of  oxygen,  it  is  positive  that 
most  of  the  chemical  changes  which  take  place  in  the  living  ani- 
mals are  accompanied  with  a  consumption  of  oxygen.  If  so, 
when  these  chemical  changes  are  diminished,  the  consumption  of 
oxygen  ought  to  diminish.  Now,  as  every  diminution  of  the 
temperature  of  an  animal  produces  a  proportionate  diminution  in 
nearly  all  the  acts  of  organic  and  animal  life,  and  as  these  acts 
are  all  accompanied  by  chemical  changes  in  which  oxygen  is 
consumed,  it  follows  that,  when  they  diminish,  the  consumption  of 
oxygen  also  diminishes. 

In  the  act  of  running,  or  in  a  rapid  walk,  we  consume  much 
more  oxygen  than  in  a  state  of  rest.  What  we  call  rest  is  merely 
a  state  of  diminished  activity;  and  when  the  temperature  of  a 
mammal  has  been  cooled  down,  the  activity  of  most  of  the  func- 
tions is  much  more  diminished  than  in  the  most  complete  rest.  It 
results  from  this  fact,  that  when  a  warm  blooded  animal  has  lost  a 
notable  part  of  its  ordinary  warmth,  its  consumption  of  oxygen 
is  much  less  than  in  a  state  of  rest. 

If  the  ligature  of  the  trachea  is  made  simultaneously  on  two 
adult  mammals  of  the  same  species,  one  of  them  being  at  its  nor- 
mal temperature,  and  the  other  at  a  temperature  of  5°  Cent. 
(9°  Fahr.)  lower,  we  observe  that  this  last  one  lives  six,  seven  or 
eight  minutes,  and  the  other  from  one  and  a  half  to  three 
minutes.  If  we  suppose  the  quantity  of  oxygen  existing  in  the 
lungs  and  in  the  blood  of  these  two  animals  is  precisely  alike  in 
both  ;  and  if  we  admit  that  death  occurs  in  asphyxia,  either  from 
want  of  oxygen  or  by  an  action  of  carbonic  acid,  in  both  cases 
these  two  animals  ought  to  live  a  different  length  of  time,  because 
the  consumption  of  oxygen  contained  in  blood  and  the  produc- 
tion of  carbonic  acid  are  quicker  in  one  of  them  than  in  the 
other.  This  explanation  is  so  true,  that  when  movements  are 


54 

excited  in  the  cooled  animal,  after  the  beginning  of  asphyxia,  it 
dies  sooner  than  when  it  remains  in  rest. 

From  the  facts  and  reasonings  which  are  related  in  this  note 
I  draw  the  following  conclusions  : 

1st.  The  temperature  of  newly-born  warm-blooded  animals 
has  a  great  influence  on  the  duration  of  their  life  when  they  are 
asphyxiated. 

2d.  There  are  very  considerable  differences  in  the  duration  of 
life  in  asphyxiated  animals  of  different  species,  even  when  the 
experiment  is  performed  in  the  same  medium,  and  while  their 
temperature  is  at  the  same  degree. 

3.  The  degree  of  the  temperature  of  adult  warm-blooded  ani- 
mals has  also  a  great  influence  on  the  duration  of  their  life  when 
they  are  asphyxiated. 

4th.  The  influence  of  the  animation  of  the  temperature  of  a 
warm-blooded  animal  on  the  duration  of  its  life  in  asphyxia, 
explains  the  persistence  of  life  in  man,  in  cases  of  cholera, 
scleroma,  and  of  some  other  diseases,  when  respiration  is  much 
diminished. 

XVIII ON   THE    CENTRAL   SEAT    OF   GENERAL   AND     OP     TACTILE 

SENSIBILITY,    AND    ON    THE    VALUE    OF   CRIES   AS     MANIFESTA- 
TIONS  OF   PAIN.* 

To  determine  where  is  the  seat  of  perception  and  of  volition  is 
one  of  the  greatest  physiological  questions.  Flourens  maintains 
that  this  seat  is  in  the  central  lobes.  Many  physiologists,  among 
whom  are  Bouillaud,  Gerdy  and  Longet,  have  published  papers 
against  the  doctrine  of  Flourens.  Their  only  important  argu- 
ment is  that  mammals  deprived  of  their  whole  encephalon,  ex- 
cept the  medulla  oblongata  and  the  pons  varolii,  continue  to 
possess  the  faculty  of  perceiving  sensations,  and  that  the  percep- 
tion of  pain  is  then  manifested  by  cries  and  agitation.  When 
the  encephalon,  says  Longet,f  is  so  much  mutilated,  in  rabbits 
and  dogs,  that  only  the  pons  varolii  and  the  medulla  ob- 
longata remain,  in  the  cranial  cavity,  these  animals,  although 
they  seem  to  be  in  a  deep  coma,  are  still  able  to  agitate  them- 
selves, and  to  cry  plaintively,  under  the  influence  of  strong 
external  irritations ;  but  if  a  sufficiently  deep  alteration  is  made 

*  See  Compfes  Rendus  de  1'Acad.  des  Sciences,  1849.  t.  xxix.  p.  672. 
f  Traite  de  Physiol.   Paris.  1850.  t.  ii,  B.  p.  38. 


55 

in  the  pons  varolii  there  is  an  immediate  cessation  of  the  'cries 
and  of  the  agitation ;  it  merely  remains  an  animal  in  whom  the 
circulation,  the  respiration  and  the  other  nutritive  functions 
are  momentarily  accomplished. 

On  cats,  rabbits  and  guinea-pigs,  I  have  obtained  a  completely 
different  result  in  performing  that  experiment.  After  I  had  re- 
moved, slice  after  slice,  and  from  forwards  backwards,  the  whole 
encephalon,  except  only  the  medulla  oblongata,  I  have  found 
that  the  mutilated  animal,  not  only  is  much  agitated,  but  cries 
plaintively  when  it  is  pinched.  If  the  medulla  oblongata  is  also 
removed,  the  cries  cease,  but  the  agitation  still  continues. 

According  to  these  experiments,  it  is  evident  that  the  pons 
varolii  is  not  the  only  seat  of  sensibility,  the  centre  of  perception 
of  tactile  impressions,  as  Longet  calls  it,  and  that  either  the 
medulla  oblongata  is  the  seat  of  general  sensibility  or  the  cries 
do  not  prove  that  there  is  a  perception. 

Longet  considers  that  the  pons  varolii  is  not  only  the  centre  of 
perception  for  sensation  of  pain,  but  also  for  tactile  impressions. 
As  to  the  tactile  sensations  he  does  not  give  the  slightest  appear- 
ance of  proof.  Certainly  neither  the  cries  nor  the  agitation  are 
sufficient  to  authorize  the  opinion  that  the  animal  has  felt  a  sen- 
sation of  tact.  If  the  existence  of  cries  could  prove  that  there 
is  a  perception  of  a  tactile  sensation,  I  should  have  to  conclude 
from  my  experiments  that  the  medulla  oblongata  is  the  seat  of 
the  faculty  of  perception  of  tactile  sensations,  for  there  are  cries 
after  the  removal  of  the  whole  encephalon  except  the  medulla  ob- 
longata, and  there  are  no  more  after  the  removal  of  this  last 
organ.  If,  instead  of  drawing  conclusions  from  the  existence  of 
cries,  we  take  notice  only  of  the  agitation,  we  are  bound  to 
conclude  that  the  spinal  cord  is  the  seat  of  the  faculty  of  percep- 
tion of  tactile  sensations,  for  after  this  organ  has  been  separated 
from  the  medulla  oblongata,  agitation  takes  place  when  a  limb  is 
pinched.* 

Cries  and  agitation  may  be  attributed  to  a  property  of  the 
nervous  centres,  which  is  completely  different  from  the  faculty  of 
perception  of  painful  or  tactile  sensations.  That  property  is  the 
reflex  faculty  of  the  true  spinal  marrow  ;f  it  is  the  property  of 

*  This  conclusion  is  maintained  as  true  by  Senac,  Caldarii,  Kay,  Legallois, 
Paton,  J.  W.  Arnold  and  many  others, 
f  As  Dr.  Marshall  Hall  calls  it. 


56 

uniting,  in  co-ordinate  movements  isolated  muscular  contractions,* 
which  is  called  by  German  physiologists  the  faculty  of  adaptation 
to  an  end.  That  property  manifests  itself  by  movements  similar  to 
those  executed  by  unmutilated  animals  when  they  feel  a  pain  ; 
and  it  happens,  sometimes,  that  these  reflex  movements  are  less 
disordered  than  the  movements  consecutive  to  a  violent  pain  in 
an  unmutilated  animal.  The  agitation  of  the  animals  deprived  of 
all  the  parts  of  their  encephalon  is  merely  the  result  of  an  action 
of  the  reflex  faculty. 

The  cries  also  appear  to  exist  only  in  consequence  of  a  re- 
flex action.  This  appears  to  be  diflicult  to  be  proved,  and  it  will 
seem  nearly  impossible  to  admit  that  cries  may  be  produced 
by  an  animal  that  has  felt  no  pain,  or  that  has  not  had  the  will 
of  crying.  We  may  consider  a  cry  as  a  noise  produced  in 
the  larynx,  as  many  times  a  quick  expiration  is  performed  when 
the  vocal  cords  are  stretched.  Now  as  the  tension  of  these  cords 
and  the  expiration  is  produced  by  muscular  contractions,  it  is 
easy  to  understand  that  these  contractions  are  produced  by  a 
reflex  action  as  well  as  the  contractions  of  the  muscles  of  the 
limbs. 

For  those  who  know  that  hiccup,  coughing,  sneezing,  vomiting 
and  so  forth,  frequently  are  mere  reflex  phenomena,  there  ought 
to  be  no  difficulty  in  admitting  that  crying  is  a  pure  reflex 
action. 

If  we  here  use  the  expressive  language  of  Flourens,  we  will 
say,  that  the  medulla  oblongata  has  the  faculty  of  uniting  in  a 
co-ordinate  movement,  the  contractions  of  the  expiratory  muscles 
and  that  of  the  tensor  muscles  of  the  glottis. 

From  the  facts  and  reasonings  contained  in  this  note  I  will 
now  draw  the  following  conclusions  : 

1st,  That  the  experiment  by  which  many  physiologists  have 
endeavored  to  prove  that  the  cerebral  lobes  are  not  the  exclusive 
seat  of  the  perceptions,  do  not  give  such  a  proof. 

2d,  That  animals  can  cry  after  the  removal  of  the  whole 
encephalon,  except  only  the  medulla  oblongata. 

3d,  That  the  existence  of  cries  cannot  prove  that  there  is 
a  perception  of  pain,  because  cries  result  from  muscular  contrac- 
tions which  may  be  pure  reflex  actions. 

*  That  is  the  name  given  by  Flourens  more  than  25  years  ago. 


57 

4th,  That  there  is  no  proof  that  the  pons  varolii  is  the  centre 
of  perceptions  either  of  touch  or  of  pain. 

5th,  That  if  it  is  admitted  that  cries  prove  that  there  is  a 
perception  of  pain,  we  should  have  to  admit  that  the  medulla 
oblongata  is  also  a  centre  for  these  perceptions. 

XIX ON   THE   MODE   OF  ACTION   OF  SOME   OF  THE   MOST   ACTIVE 

POISONS    UPON   THE   NERVOUS   SYSTEM. 

Some  of  the  results  of  my  experiments  on  this  subject  have 
already  been  published  in  the  inaugural  dissertation  of  my 
learned  friend  and  pupil,  Dr.  F.  W.  Bonnefin,  with  whom  I  per- 
formed most  of  these  experiments.* 

I  intend  to  give  here  only  the  results  of  my  researches  on  the 
poisons  which  produce  convulsions.  For  the  sake  of  brevity  I 
have  called  them  convulsing  poisons.  The  most  important 
among  them  are  :  strychnine,  brucine,  picrotoxine,  morphine, 
digitaline,  cyanhydric  acid,  nicotine,  cyanide  of  mercury,  sul- 
phide of  carbon,  chloride  of  barium,  and  oxalic  acid. 

The  principal  questions  which  I  have  endeavored  to  solve  are 
the  following  : 

1.  What  is  the   part  of  the  animal  frame  upon  which  these 
poisons  act  in  producing  convulsions  ? 

2.  By  what  mode  of  action  do  they  produce  convulsions  ? 
The  parts  of  the  body  on  which  they  could  act  are  : — 

a.  The  nervous  centres. 

b.  The  motor  or  centrifugal  nerves. 

c.  The  sensitive  or  centripetal  nerves. 

d.  The  muscles. 

Of  course,  the  convulsing  poisons  could  act  upon  these  four 
parts  together,  or  upon  two  or  three  of  them. 

Now,  as  to  the  mode  of  action,  these  poisons  could  produce 
convulsions  directly  or  indirectly. 

In  other  words  these  poisons  might  act  : — 1.  As  excitants 
either  of  the  muscles  or  of  the  nervous  system,  and  this  is  what 
I  call  a  direct  action.  2.  As  causes  of  increase  of  the  vital 
powers  of  the  muscles  or  of  the  nervous  system,  so  that  even  a 
slight  excitation  of  these  parts  is  able  to  produce  convulsions, 
and  this  is  what  I  call  an  indirect  action. 

*  Rech.  Experim.  sur  Faction  convulsivante  des  priucipaux  Poisons,  in  4 
Paris,  1851. 


58 

The  convulsing  poisons  do  not  appear  to  excite  the  muscles 
or  any  part  of  the  nervous  system,  and  consequently  they  do  not 
act  directly.  They  act  merely  in  increasing  the  vital  powers  of 
the  nervous  system,  so  that  a  slight  excitation  of  the  skin  or  ano- 
ther part  where  there  exist  nerves  of  sensation  is  sufficient  to  pro- 
duce convulsions.  Therefore  these  poisons  act  indirectly  in  the  pro- 
duction of  convulsions.  They  do  not  produce  convulsions,  they 
merely  act  upon  the  nervous  system,  so  as  to  render  it  capable  of 
producing  convulsions  when  it  receives  an  excitation.  They  do 
not  excite  the  nervous  system,  and  their  mode  of  action  is  altoge- 
ther different  from  that  of  the  mechanical,  physical,  and  chemical 
excitations  which  directly  produce  convulsions,  when  they  are 
applied  to  the  medulla  oblongata,  or  to  the  spinal  cord. 

This  mode  of  action  was  already  known  as  regards  strych- 
nine. Long  ago  Mr.  Magendie*  found  that  animals  poisoned 
by  nux  vomica,  frequently  remain  without  convulsions  as  long  as 
they  are  left  without  excitation,  but  that  fits  are  immediately 
produced  when  they  are  touched.  Since  that  time  Stannius,j- 
Van  Deen,{  Pickford,||  J.  W.  Arnold,§  Meyer,  of  Zurich,!!  Mar- 
shall Hall,**  and  A.  Barnard, ff  have  observed  many  facts 
proving  that  strychnine  does  not  directly  produce  convulsions. 
The  following  experiment,  which  I  performed  with  the  assistance 
of  Dr.  Bonnefin,  is  still  more  demonstrative. 

I  introduce  a  large  dose  of  strychnine  into  the  stomach  of  a  frog, 
after  the  removal  of  its  brain  and  of  its  medulla  oblongata.  As 
the  voluntary  and  the  respiratory  movements  are  then  impossi- 
ble, there  is  no  spontaneous  movement  at  all,  and  if  the  animal 
is  left  perfectly  quiet  there  are  no  convulsions.  But  as  soon  as 
it  is  excited,  even  by  the  slightest  touch,  tetanus  occurs. 

In  this  case,  it  is  evident  that  the  convulsive  fit  is  merely  a  re- 

*  Rxamen  de  I'action  de  quelques  vegetaux  sur  la  Moelle  epiniere.  Paris 
1809,  p.  7. 

t  Mueller's  Archiv.  1837,  p.  223. 

jTraites  et  deeouvertes  sur  la  Moelle  epiniere,  1841.  p.  123, 
||  In  Rorer  und  lTrar(|erlich'8  Vieiteljaheschrift.     Bil.  2.  1843;  p.  430. 
§  Ueberdie  verrichtunsj  der  VVerzeln  der  Ruckenmarksnerven,  1844. 
T  Schmidt's  Jahrbuc-her,  1847,  No.  8. 

**  Comptes  rendusde  1'Acad.  des  Sciences,  1847,  vol.24,  p.  1054. 
ff  Proces  verbaux  de  la  Societe  Philoinatique,  1847;  p.  71. 


59 

flex  act.  But  why  is  there  a  tetanic  contraction  instead  of  the 
regular  reflex  movements  ?  The  reason  is  that  the  reflex  faculty 
is  considerably  increased.  This  will  be  proved  in  a  moment. 

Before  giving  this  demonstration,  I  must  examine  if  there  is 
not  also  an  increase  in  the  vital  powers  of  the  muscles  and  of  the 
motor  nerves.  There  was  no  reason  to  reject  the  supposition  that 
the  convulsing  poisons  were  capable  of  increasing  simultaneously 
the  vital  powers  of  the  nervous  centres,  of  the  nerves,  and  of  the 
muscles.  Consequently,  I  was  led  to  perform  the  following 
experiments,  which  prove  : — 1st,  that  these  poisons  do  not 
increase  the  vital  powers  of  the  motor  nerves  and  of  muscles ; 
2d,  that  they  do  not  act  as  direct  excitants  upon  these  organs. 

On  young  cats,  on  birds,  and  on  reptiles,  I  removed  the  whole 
portion  of  the  spinal  cord  which  supplies  nerves  to  the  posterior 
limbs.  A  few  minutes  after,  I  injected  into  the  rectum  a 
solution  of  a  salt  of  strychnine.  Convulsions  occurred  only  in 
the  anterior  parts  of  the  body,  and  when  I  excited  either  the 
motor  nerves  or  the  muscles  of  the  posterior  limbs,  contrac- 
tions were  produced  exactly  as  in  animals  not  poisoned,  but 
there  was  no  appearance  of  convulsions. 

When  the  poison  was  placed  directly  on  muscles  or  on 
nerves,  or  when  it  was  injected  with  blood  in  a  limb  separated 
from  the  body,  there  was  no  appearance  either  of  an  exci- 
tation, or  of  an  increase  in  the  excitability  of  the  muscles,  or  of 
the  mDtor  nerves. 

The  experiments  of  Magendie,  of  Emmert,*  and  of  Backer,f 
have  demonstrated  that  after  a  transverse  section  of  the  spinal 
cord,  between  its  two  enlargements,  convulsions  may  be  produced 
in  the  palsied  limbs,  when  the  animal  is  poisoned  with  strychnine. 
All  the  physiologists  who  have  performed  this  experiment  have 
found  it  perfectly  exact.  Nevertheless,  J.  W.  Arnold, J  maintains 
that  the  action  is  much  less  considerable  in  the  posterior  limbs, 
in  that  case,  than  when  the  spinal  cord  is  uninjured  and  united 
with  the  medulla  oblongata,  and  he  concludes  that  the  poison 

*  Exper.  de  effectu  venenorum  veget.  americ.  in  corpus  animale,  1817. 
"I"  Commentatio  ad  questionem  physio).,  ab  Acad.     Rheno  traject,  anno 
1828,  propositam. 

J  Die  lehre  von  der  Reflex-function.     Chap.  ix.  and  x.     1842. 


60 

acts  much  more  on  the  medulla  oblongata  than  on  the  spinal 
cord. 

Sometimes,  as  Arnold  says,  it  occurs  that  the  action  of  strych- 
nine, in  mammalia  and  in  amphibia,  is  not  so  powerful  in  the 
palsied  parts,  after  the  section  of  the  spinal  cord,  as  in  the 
non-palsied  limbs.  As  to  mammalia,  the  reason  of  this  difference 
is  the  diminution  in  the  quantity  of  blood  received  by  the  part 
of  the  spinal  marrow  separated  from  the  encephalon.  As  to 
amphibia,  it  is  easily  seen  that  immediately  after  the  section  of 
their  spinal  cord,  the  reflex  faculty  in  the  part  separated  from 
the  encephalon  is  very  weak,  and  if,  then,  strychnine  is  given  to 
the  animal,  it  does  not  act  very  strongly  ;  but  if  the  poison  is 
given  two  or  three  hours  after  the  section  of  the  spinal  cord, 
then  the  reflex  faculty  is  very  powerful  and  the  poison  acts  vio- 
lently, and  sometimes  more  than  if  the  spinal  cord  was  uninjured. 
In  birds,  which,  as  I  have  discovered,  have  constantly  a  power- 
ful reflex  faculty  after  the  section  of  the  spinal  cord,  strychnine 
acts  very  energetically. 

Lately,  Stannius  and  Cl.  Bernard  have  supposed  that  strych- 
nine, instead  of  acting  on  the  spinal  marrow,  acted  on  the  nerves 
of  sensibility,  and  more  particularly  on  their  termination  in  the 
skin.  They  base  this  hypothesis  on  some  experiments,  of  which 
only  one  is  important.  After  the  section  of  the  spinal  cord,  at 
the  brachial  enlargement,  upon  a  frog,  the  animal  is  poisoned 
with  strychnine,  and  then  convulsions  occur  nearly  at  each  vo- 
luntary or  respiratory  movement.  But  if  the  sensitive  roots  of 
the  spinal  nerves  are  cut,  the  convulsions  cease  immediately. 

Now,  it  is  evident  that  this  fact  does  not  prove  what  Stannius 
and  Bernard  have  supposed ;  because  it  may  be  explained  as 
well  by  admitting  that  convulsions  are  produced  only  in  conse- 
quence of  an  increase  of  the  reflex  faculty  of  the  spinal  cord, 
as  by  the  hypothesis  of  Stannius. 

Van  Deen  *  relates  an  experiment  which  is  in  opposition  to 
the  theory  of  Stannius.  If  we  take  a  frog  prepared  exactly  as 
in  the  experiment  of  this  physiologist,  we  see  that  tetanus  oc- 
curs when  the  animal  is  thrown  on  the  floor.  In  this  case 
tetanus  is  produced,  although  the  sensitive  roots  are  cut  and 
unable  to  act ;  therefore  tetanus  is  a  consequence  of  an  increased 

*  Loco  cit.  p.  123. 


61 

vitality  in  the  spinal  cord  itself.  But  this  experiment  is  not 
decisive,  because  sometimes  it  occurs  that  such  a  mechanical 
excitation  in  frogs,  which  have  not  been  poisoned,  produces 
tetanus.  Nevertheless  I  must  say  that  the  tetanus  in  this  last 
case  is  never  so  violent  as  in  poisoned  frogs. 

A  better  experiment  is  to  excite  slightly  with  a  needle,  the 
posterior  columns  of  the  spinal  cord.  Then,  tetanus  constantly 
occurs  in  poisoned  frogs,  although  the  sensitive  roots  are  divided, 
and  it  very  rarely  occurs  in  frogs  that  are  not  poisoned. 

I  have  already  published*  the  following  experiments,  which 
are  much  more  decisive  against  the  hypothesis  of  Stannius : 

A  ligature  is  put  around  the  aorta  of  a  frog,  near  its  termi- 
nation in  the  abdomen,  and  consequently  the  posterior  limbs 
cease  to  receive  blood.  Then  the  frog  is  poisoned  with  strych- 
nine introduced  into  its  mouth,  and  after  a  few  minutes  the 
convulsive  phenomena  take  place. 

In  this  experiment  the  nerves  of  the  posterior  limbs  do  not 
receive  strychnine,  whilst  the  spinal  cord  receives  it ;  therefore 
convulsions  are  not  produced  ia  consequence  of  an  action  of 
strychnine  on  the  sensitive  nerves  of  the  skin,  as  Stannius  has 
supposed,  but  in  consequence  of  its  action  on  the  spinal  cord. 

Now,  if  we  poison  a  frog  after  having  divided  the  spinal  cord 
at  the  brachial  enlargement,  and  after  the  section  of  all  the 
small  arteries  giving  blood  to  the  spinal  column,  we  see  that 
convulsions  do  not  take  place  in  the  posterior  limbs,  although 
the  reflex  faculty  is  not  lost  in  consequence  of  the  cessation  of 
the  circulation  in  the  spinal  cord,  and  that  it  remains  for  half  an 
hour  or  a  little  more  in  summer,  and  about  two  hours  in  winter. 

In  this  experiment,  blood  containing  strychnine  reaches  the 
sensitive  nerves  of  the  posterior  limbs,  and  not  the  spinal 
cord,  and  there  are  no  convulsions;  therefore  it  is  not  on  the 
sensitive  nerves  that  strychnine  acts  in  order  to  produce  con- 
vulsions. 

These  two  experiments  are  evidently  decisive.    In  the  first,  we 
see  that  when  blood  containing  strychnine   reaches  the   spinal 
cord,    and    not  the    cutaneous  nerves,  there   are  convulsions ; 
and  in  the  second,  we  see  that  when  blood  containing  strychnine 
reaches  the  sensitive  nerves   and   not-  the    spinal   cord,    there 
*  Gaz.  Med.  de  Paris,  1849,  p.  745. 
6 


62 

are  no  convulsions.     We  must  consequently  draw  from  these  ex- 
periments  these  two  conclusions : 

1.  Strychnine  does  not  act  upon  the  sensitive  nerves. 

2.  Strychnine  acts  upon  the  spinal  cord. 

Now,  from  all  the  facts  above  related,  two  other  conclusions 
are  to  be  drawn: 

1.  Strychnine  does  not  excite  the  nervous  system  ;  or,  in  other 
words,  strychnine  does  not  produce  convulsions  directly. 

2.  Strychnine  increases  the  reflex  faculty  of  the  spinal  cord, 
and  so  produces  convulsions  indirectly. 

I  do  not  intend  to  examine  here  whether  strychnine  kills  in 
producing  convulsions,  or  by  another  action.  Nevertheless,  I 
will  say,  that  although  convulsions  are  sufficient  to  kill  in 
asphyxiating,  death,  in  cases  of  poisoning  by  strychnine,  may 
be  also  produced  by  another  action  of  that  poison.  I  have  seen 
animals  in  which  convulsions  did  not  take  place  at  all,  and 
which  have  been  killed  by  strychnine. 

The  other  convulsing  poisons  that  I  have  studied,  appear  to 
act  as  strychnine,  as  to  the  production  of  convulsions. 

The  same  experiments  which  I  have  related  as  regards 
strychnine,  have  been  performed  with  these  poisons,  and  I  have 
obtained  the  same  results.  Sometimes,  nevertheless,  I  found 
some  differences ;  and,  for  instance,  it  appears  that  the  chloride 
of  barium  is  a  direct  exciter  of  the  muscular  fibres,  and  cyan- 
hydric  and  oxalic  acids  seem  also  to  be  slight  but  direct  exciters 
of  the  spinal  cord. 

The  action  of  the  chloride  of  barium  is  very  important,  be- 
cause that  poison  is  an  exciter  of  the  muscular  fibres,  and  not  of 
the  nerves.  This  fact  proves  that  the  muscular  irritability  may 
be  put  in  action  without  the  intervention  of  the  nerves. 

The  increase  of  the  reflex  faculty,  by  the  convulsing  poisons, 
is  a  very  important  fact.  How  is  that  increase  produced  ?  We 
believe  it  takes  place  in  consequence  of  an  increase  in  the  nutri- 
tion of  the  nervous  centres.  J.  Mueller*  is  of  opinion  that 
there  is  no  substance  able  to  increase  directly  the  vital  proper- 
ties of  any  organ.  He  says  that  nutrition  alone  is  able  to  pro- 
duce such  an  effect.  I  believe  he  is  perfectly  right,  and  I  ad- 
mit that  the  mode  of  action  of  the  convulsing  poisons,  in  the 

*  Manuel  de  Physiol.,  edited  by  Littre,  1851,  t.  i.  p.  582. 


63 

production  of  convulsions,  is  merely  to  increase  nutrition  in  the 
nervous  centres.  It  is  important  for  practitioners  to  know  that 
mode  of  action.  The  usefulness  of  strychnine  in  many  cases  of 
palsy,  may  be  explained  very  easily  by  that  action.  I  have 
frequently  seen,  in  the  wards  of  the  hospital  la  Charite  at  Paris, 
paralytics  under  the  care  of  Dr.  Rayer,  taking  strychnine. 
Every  day  the  reflex  faculty  was  increasing  in  them  as  long  as 
they  took  that  substance ;  and  on  the  contrary,  when  the  use  of 
that  medicament  was  stopped,  the  reflex  faculty  began  immediately 
to  dimmish,  and  in  some  patients  it  disappeared.  If  strychnine 
was  given  anew,  the  reflex  faculty  was  still  increased.  These 
facts  have  been  recorded  with  great  care  by  my  learned  friend, 
Mr.  Chareot.  I  hope  he  will  publish  them. 

From  all  the  facts  narrated  in  this  paper,  I  believe  I  am  enti- 
tled to  draw  the  following  conclusions : 

1.  The    convulsing    poisons,  more   particularly   strychnine, 
brucine,  picrotoxine,  cyanhydric  acid,  nicotine,  morphine,  cyanide 
of  mercury,  sulphide  of  carbon,   digitaline,  oxalic  acid,  appear 
to  produce  convulsions,  without  acting   either  directly  or  indi- 
rectly on  the  muscles  or  on  the  motor  or  sensitive  nerves. 

2.  Generally  these  poisons  do  not  appear  to  produce  convul- 
sions in  acting  directly  on  any  part  of  the  nervous  centres. 

3.  These  poisons,  in  producing  convulsions,  act  only  on  the 
parts  of  the  nervous  system  endowed  with  the  reflex  faculty. 

4.  The  mode  of  action  of  these  poisons  consists  in  the  increase 
of  the  nutrition  of  the  nervous   centres,  by   which   excess  of 
nutrition  the  reflex  faculty  becomes  much  increased. 

XX.— -ON  THE    CROSSED    TRANSMISSION    OF    IMPRESSIONS    IN   THE 
SPINAL   CORD. 

Numerous  experiments  which  I  have  performed  have  proved 
to  the  numerous  physicians  and  students,  who  have  seen 
the  most  important  of  them,  that  the  impressions  made  on  one 
side  of  the  body  are  transmitted  to  the  sensorium  by  the  oppo- 
site side  of  the  spinal  cord. 

It  is  known  that  Galen*  performed  two   experiments,  which 

*  See :  De  locis  affectis,  lib.  iii.  cap.  xiv ;  or  De  anatomicis  admonstra- 
tionibus,  lib.  viii.  sect.  6. 


64 

have  been  considered  as  demonstrating  that  there  is  no  crossed 
action  in  the  spinal  cord. 

One  of  these  experiments  of  Galen  consisted  in  the  transver- 
sal section  of  a  lateral  half  of  the  spinal  marrow.  After  this 
operation  the  animal  was  paralyzed  in  all  the  parts  situated  be. 
hind  the  section,  on  the  same  side,  so  that  the  palsy  was  on  the 
right  side  of  the  body  when  the  right  side  of  the  spinal  cord  was 
divided,  and  vice  versa. 

The  second  experiment  consisted  in  a  longitudinal  section  on 
the  middle  line  of  the  spinal  cord  so  as  to  separate  into  two  late- 
ral halves  the  part  of  that  nervous  centre  supplying  nerves  to  the 
posterior  limbs.  After  this  operation  the  animal  was  able  to 
walk. 

Galen,  in  these  two  experiments  did  not  examine  the  state  of 
the  sensibility.  He  speaks  merely  of  the  voluntary  movements. 
Nevertheless  his  researches  were  considered  in  this  century  as 
completely  proving  that  there  is  no  crossing  of  action  in  the 
spinal  cord,  either  for  sensibility  or  for  voluntary  movement. 

The  following  experiments  will  prove  that  there  is  a  crossing 
of  action  for  sensibility  in  that  organ  : 

1st.  If  a  lateral  half  (i.  e.  the  posterior  and  the  antero-lateral 
columns  and  the  gray  matter  of  one  side  of  the  spinal  cord),  is 
divided  transversely  at  the  level  of  the  tenth  costal  vertebra,  on 
a  mammal,  it  is  soon  evident  that  the  sensibility  is  much  dimin- 
ished in  the  posterior  limb  opposite  to  the  side  of  the  sections. 
On  the  contrary  the  sensibility  instead  of  being  lost  appears 
much  increased  in  the  posterior  limb  on  the  side  where  the  sec- 
tion  has  been  made. 

2d.  If,  instead  of  one  transversal  section  of  the  spinal  cord, 
two,  three,  four  or  many  more  are  made  on  the  same  lateral  half 
of  that  organ,  the  same  results  are  obtained. 

3d.  If,  instead  of  mere  sections,  a  removal  of  a  part  of  a 
lateral  half  of  the  spinal  cord,  is  effected,  the  same  results  are 
still  obtained.  In  performing  this  experiment  a  longitudinal 
section,  one  inch  in  length,  from  behind  forward,  is  made  in  the 
median  plane  of  the  spinal  marrow,  and  then  two  transversal  sec- 
tions on  a  lateral  half  are  made  at  the  extremities  of  the  longi- 
tudinal section,  so  that  a  part  of  the  cord  is  completely  separa- 
ted from  that  organ  and  afterwards  removed. 


65 

4th.  If  instead  of  dividing  entirely  a  lateral  half  of  the  spi- 
nal cord,  a  small  part  is  left  undivided  towards  the  centre  of 
that  organ,  the  posterior  limb  on  the  same  side  becomes  much 
more  sensible,  but  the  posterior  limb  on  the  opposite  side  remains 
very  sensible  and  sometimes  it  appears  more  sensible  than  in  the 
normal  state. 

5th.  If  in  performing  the  section  of  a  lateral  half  of  the  spi- 
nal cord  the  instrument  goes  a  little  too  far  and  divides  also  a 
small  portion  of  the  other  half,  then  the  posterior  limb  on  the 
side  of  the  complete  section  is  less  sensible  than  in  the  normal 
state,  and  the  posterior  limb  of  the  opposite  side,  loses  com- 
pletely its  sensibility. 

6th.  If  the  section  of  a  lateral  half  of  the  spinal  cord  is  made 
at  the  level  of  the  second  or  third  cervical  vertebra,  it  is  found 
that  the  sensibility  becomes  very  quickly  much  greater  in  the 
parts  of  the  body  on  the  same  side  as  the  section,  and  on  the 
contrary  the  parts  on  the  other  side  becomes  evidently  less  sen- 
sible. 

7th.  If  after  a  section  of  a  lateral  half  of  the  spinal  cord  at 
the  level  of  the  eleventh  costal  vertebra,  another  section  is  per- 
formed on  the  other  side  of  that  organ,  at  the  level  of  the  sixth 
costal  vertebra,  so  that  the  two  lateral  halves  are  divided,  then 
sensibility  in  most  of  the  cases  is  lost,  on  both  sides.  Some- 
times it  retains  a  very  slight  degree  of  sensibility,  more  parti- 
cularly in  the  posterior  limb  on  the  side  where  the  spinal  cord 
has  been  divided  at  the  level  of  the  sixth  costal  vertebra. 

8th.  If  two  sections  of  lateral  halves  are  made  as  in  the  pre- 
ceding experiment,  but  at  a  greater  distance,  one  from  the  other, 
on  the  right  side  for  instance  at  the  level  of  the  twelfth  costal 
vertebra,  and  on  the  left  side  in  the  cervical  region,  nearly  the 
same  results  are  obtained  as  to  the  posterior  limbs,  but  the  sen- 
sibility is  increased  in  the  right  anterior  limb  and  it  remains  very 
evidently,  but  much  diminished,  in  the  left  anterior  limb. 

9th.  If  a  longitudinal  section  is  made  on  the  part  of  the 
spinal  cord  giving  nerves  to  the  posterior  extremity,  so  as  to 
divide  that  part  into  two  lateral  halves,  then  it  is  found  that  sen- 
sibility is  completely  lost  in  the  two  posterior  limbs,  although 
voluntary  movements  take  place  in  them. 

10th.  If  a  similar  separation  of  two  lateral  halves  of  the  spi- 

6* 


66 

nal  cord  is  made'on  the  whole  part  supplying  nerves  to  the  anterior 
limbs,  then  it  is  found  that  sensibility  is  lost  in  both  these  limbs, 
and  that  it  is  only  slightly  diminished  in  the  posterior  limbs. 

llth.  If  the  same  operation  is  done  as  in  the  preceding  expe- 
riment, and  afterwards  if  a  transversal  division  is  made  on  one 
of  the  lateral  halves,  in  the  place  where  it  is  separated  from  the 
other,  then  it  is  found  that  the  posterior  limb  on  the  side  of  the 
transversal  section  remains  sensible,  and  that  the  other  posterior 
limb  loses  its  sensibility. 

These  experiments  prove  very  clearly  that  the  sensitive  ner- 
vous fibres  are  crossed  in  the  spinal  cord.  The  9th,  10th,  and 
llth,  demonstrate  directly  the  crossing.  In  these  experiments 
the  crossed  fibres  are  all  cut,  and  sensibility  is  lost.  This  fact 
appears  to  prove  that  all  the  sensitive  fibres  cross  each  other  ; 
but  it  will  be  easily  understood  that  on  account  of  the  loss  of 
blood,  and  of  the  general  diminution  of  sensibility  produced  by 
the  excessive  pain  of  the  operation,  if  there  are  some  fibres 
which  remain  without  crossing,  they  are  insufficient  to  give 
sensations. 

As  to  the  experiments  consisting  in  transversal  sections  of  a 
lateral  half,  they  prove  that  sensibility  is  much  diminished  in  the 
side  of  the  body  opposite  to  that  of  the  section ;  consequently 
they  prove  also  that  there  is  a  crossing  of  a  great  part  of  the 
sensitive  fibres. 

The  fact  that  transmission  of  impressions  made  on  one  side  of 
the  body  takes  place,  at  least  for  a  great  part,  in  the  opposite 
side  of  the  spinal  cord,  is  proved  evidently  by  the  eight  first 
experiments,  but  much  more  by  the  7th  and  the  8th  experiments 
in  which  it  is  found  that,  after  a  section  of  a  lateral  half  of  the 
spinal  cord,  sensibility  remains  on  the  same  side,  and  that  it  is 
nearly  entirely  lost  after  a  second  section  of  the  other  lateral 
half  in  another  place. 

If  most  of  the  nervous  sensitive  fibres  are  crossed  in  the 
spinal  cord,  then  it  is  not  exact  to  admit  that  the  crossed  paraly- 
sis of  sensibility  in  cases  of  diseases  of  the  brain,  is  explained 
by  the  crossing  of  fibres  which  exists  in  the  pons  Varolii  and  in 
other  parts  of  the  encephalon.  Many  opinions  have  been  pro- 
posed as  regards  the  place  where  the  sensitive  nervous  fibres 
make  their  crossing  in  the  encephalon.  According  to  some  pa- 


67 

thologists,  this  crossing  takes  place  all  along  the  medulla  oblon- 
gata,  the  pons  Varolii,  tubercula  quadrigemina  and  the  crura 
cerebri.  In  all  these  organs  there  is  truly  a  crossing  of  fibres, 
but  we  do  not  know  what  are  these  fibres.  Ch.  Bell  believes 
that  the  crossing  of  the  sensitive  fibres  takes  place  in  the  poste- 
rior surface  of  the  medulla  oblongata,  in  a  great  part  of  the 
length  of  the  fourth  ventricle.  Longet  supposes  that  this  cros- 
sing exists  at  the  anterior  border  of  the  pons  Varolii,  where  the 
two  processi  cerebelli  ad  testes  cross  each  other. 

My  experiments  prove  that  if  there  are  some  fibres  coming 
from  the  trunk  and  from  the  limbs  which  do  not  effect  their 
crossing  in  the  spinal  cord  itself,  their  number  ought  to  be  very 
small.  Therefore  the  fibres  which  are  found  crossed  in  the  ence- 
phalon  are  not  sensitive  fibres  coining  from  the  limbs  and  from 
the  trunk,  as  all  physiologists  have  supposed  they  were. 

My  experiments  were  made  on  many  different  species ; 
guinea-pigs,  dogs,  cats,  sheep,  and  rabbits.  In  all  the  same  re- 
sults were  obtained. 

To  ascertain  the  degree  of  sensibility,  I  used  various  modes 
of  excitation ;  mechanical,  galvanic,  physical,  (i.  e.  warmth 
and  cold,)  and  chemical.  I  constantly  compared  the  degrees 
of  sensibility  in  the  parts  of  the  body  situated  behind  the  in- 
jured portion  of  the  spinal  cord,  with  the  anterior  parts  of  the 
body,  and  particularly  with  the  face.  It  is  thus  that  I  have  been 
able  to  ascertain  the  existence  of  an  increase  or  of  a  diminution 
in  sensibility. 

Sometimes  I  have  given  chloroform  to  animals  having  had  a 
lateral  half  of  the  spinal  cord  divided  in  the  cervical  region. 
I  have  found  that  complete  loss  of  sensibility  appeared  at 
first  in  the  parts  of  the  body  opposite  to  the  section  of  the  spinal 
cord,  the  head  and  neck,  and  at  last  in  the  parts  of  the  body  be- 
hind the  section  of  the  cord,  on  the  same  side.  This  experiment, 
as  well  as'many  others,  prove  undoubtedly  that  there  is  an  increase 
of  sensibility  in  these  last  parts.  I  will  try  in  another  article  to 
explain  this  hyperaDSthesia. 

I  believe  I  am  entitled  to  conclude  from  the  facts  above  re- 
lated : 

1st.  That  most  of  the  impressions  made  on  one  side  of  the 
body  are  transmitted  to  the  sensorium  by  the  opposite  side  of 


68 

the  spinal  cord,  so  that  the  impressions  on  the  left  side  of  the 
body  are  transmitted  by  the  right  side  of  the  spinal  cord,  and 
vice  versa. 

2d.  That  the  assumed  function  of  the  crossing  of  fibres  in  the 
pons  Varolii,  and  the  neighboring  parts,  does  not  belong  to  these 
fibres,  but  to  the  fibres  of  the  spinal  cord,  all  along  which  they 
cross  each  other. 

XXI . — ON  MUSCULAR   IRRITABILITY    IN    PARALYZED  LIMBS,    AND    ITS 
SEMEIOLOGICAL  VALUE. 

Marshall  Hall  has  published  many  papers,  in  which  he  has  tried  to 
prove  that  the  degree  of  muscular  irritability  in  paralyzed  parts  maybe 
used  as  a  means  of  diagnosis  between  cerebral  and  spinal  paralysis. 

He  calls  cerebral  paralysis  that  in  which  the  paralyzed  part  is  de- 
prived of  the  action  of  the  brain,  but  not  entirely,  or  not  in  the  least,  of 
the  influence  of  the  spinal  cord.  On  the  contrary,  he  calls  spinal 
paralysis  that  in  which  the  palsied  part  is  altogether  deprived  of 
the  action  of  both  the  brain  and  the  spinal  marrow.  The  cause 
of  the  cerebral  paralysis  may  be  seated  either  in  the  encephalon  or 
the  spinal  cord;  and  the  cause  of  the  spinal  paralysis  may  be  seated 
either  in  the  spinal  cord  or  in  the  nerves. 

In  the  same  individual  these  two  kinds  of  paralysis  may  exist 
together.  Suppose  a  man  in  whom  the  brachial  enlargement  of 
the  spinal  cord  is  considerably  softened,  and  consequently  unable 
to  act ;  the  upper  limbs  then  have  a  spinal  paralysis,  and  the 
lower  limbs,  receiving  their  nerves  from  a  healthy  part  of  the  spinal 
cord,  have  only  a  cerebral  paralysis. 

According  to  Marshall  Hall,  the  cerebral  paralysis  is  attended  by 
augmented  muscular  irritability,  and  the  spinal  paralysis  is  attended 
by  diminished  irritability.  He  bases  this  opinion  on  the  following 
experiments,  and  on  some  clinical  observations. 

On  six  frogs  he  divided  the  spinal  marrow  immediately  below 
the  origin  of  the  brachial  nerves  ;  and  he  removed  a  portion  of  the 
ischiatic  nerve  of  the  right  posterior  extremity.  He  had  imme- 
diately, or  more  remotely,  the  following  interesting  phenomena  : 

1st.  The  anterior  extremities  alone  were  moved  spontaneously; 
both  posterior  extremities  remaining  entirely  motionless  when  the 
animal,  placed  on  its  back,  made  ineffectual  efforts  to  turn  on  the 
abdomen. 


69 

2d.  Although  perfectly  paralytic  in  regard  to  spontaneous  motion, 
the  left  posterior  extremity,  that  still  in  connexion  with  the  spinal 
marrow,  moved  very  energetically  when  stimulated  by  pinching  the 
toes  with  the  forceps. 

3d.  The  right  posterior  extremity,  or  that  of  which  the  ischiatic 
neive  was  divided,  was  entirely  paralytic,  both  in  reference  to  spon- 
taneous and  excited  motions. 

4th.  After  the  lapse  of  several  weeks,  whilst  the  muscular  irri- 
tability of  the  left  posterior  extremity  was  gradually  augmented,  that 
of  the  right  was  gradually  diminished, — phenomena  observed  when 
the  animal  was  placed  in  water  through  which  a  slight  galvanic 
shock  was  passed  accurately  in  the  direction  of  the  mesial  plane. 

5th.  Strychnine  being  now  administered,  the  anterior  extremities 
and  the  left  posterior  extremity,  or  that  still  in  connexion  with  the 
spinal  marrow,  became  affected  with  tetanus ;  but  the  right  poste- 
rior extremity,  or  that  severed  from  all  nervous  connexion  with  the 
spinal  marrow,  remained  perfectly  placid. 

6th.  Lastly,  the  difference  in  the  degree  of  irritability  in  the  mus- 
cular fibre  of  the  two  limbs  was  observed,  when  these  were  entirely 
separated  from  the  rest  of  the  animal. 

After  this  exposition  of  the  results  of  his  experiments,  Marshall 
Hall  adds  :  **  In  a  word,  the  muscles  of  the  limb  paralyzed  by  its 
separation  from  both  cerebrum  and  spinal  marrow,  had  lost  their 
irritability  ;  whilst  those  of  the  limb  separated  from  its  connexion 
with  the  cerebrum  only,  but  left  in  connexion  with  the  spinal  mar- 
row, not  only  retained  their  irritability,  but  probably  possessed  it  in 
an  augmented  degree.* 

It  is  easy  to  prove  that  Marshall  Hall  has  been  completely  mis- 
led by  his  experiments. 

It  is  well  known  that  the  more  a  muscle  is  excited,  the  more  it 
contracts.  As  the  degree  of  irritability  is  judged  by  the  degree  of 
the  contraction,  it  follows  that  to  know  what  is  the  degree  of  mus- 
cular irritability  we  ought  to  apply  the  same  excitation  to  the  mus- 
cles we  desire  to  compare.  In  his  experiments  with  galvanism  and 
with  strychnine,  Marshall  Hall  has  not  done  so.  He  has  applied 

*  On  the  diseases  and  derangements  of  the  nervous  system.  1841,  p. 
215. 


70 

galvanism,  so  as  to  excite  much  more  the  muscles  of  the  left  side 
united  with  the  spinal  cord,  than  those  of  the  right  side. 

The  muscles  of  the  left  side  were  excited  : 

1st.  Directly  by  the  galvanic  current. 

2d.  In  consequence  of  the  excitation  of  the  motor  nerves. 

3d.  In  consequence  of  the  excitation  of  the  spinal  cord,  directly 
by  the  galvanic  current,  and  secondarily  in  consequence  of  the 
excitation  of  the  sensitive  nerves. 

So  that  the  muscles  on  that  side  were  moved  not  only  by  the 
direct  excitation  on  them,  but  also  by  a  reflex  action,  and  in  conse- 
quence of  the  direct  excitation  of  the  spinal  cord. 

As  to  the  muscles  of  the  right  side,  they  were  only  excited  by 
the  small  part  of  the  galvanic  current  passing  in  them.  During  the 
first,  and  perhaps  the  second  and  the  third  week  after  the  section  of 
the  ischiatic  nerve,  the  muscles  were  also  slightly  excited  by  the 
motor  fibres  of  that  nerve,  but  after  that  time  these  fibres  had  lost 
their  vital  property,  and  were  unable  to  excite  a  contraction  in 
muscles. 

From  this  analysis  it  results  clearly  that  the  mode  of  comparison 
of  the  two  limbs,  by  the  passage  of  a  galvanic  current,  as  it  has 
been  employed  by  Marshall  Hall,  could  not  decide  in  which  side 
the  muscles  were  more  irritable. 

The  use  of  strychnine,  also,  could  decide  nothing  in  this  ques- 
tion, because,  as  I  have  proved  in  a  former  article,  this  poison  is  not 
able  to  act  upon  muscles.  It  acts  only  on  the  nervous  centres,  and 
especially  on  the  spinal  cord.  Therefore,  the  production  of  tetanus 
in  one  limb  and  not  in  the  other,  in  the  experiment  of  Marshall 
Hall,  proves  nothing  at  all  as  to  the  degree  of  muscular  irritability. 

To  know  what  is  that  degree,  it  is  necessary  to  separate  the  two 
limbs  from  the  trunk,  and  then  to  excite  directly  the  muscles.  Mar- 
shall Hall  has  made  this  experiment,  but  he  says  nothing  about  the 
circumstances  under  which  it  was  performed,  and  these  circum- 
stances were,  as  it  will  be  shown,  extremely  important. 

In  my  experiments,  instead  of  dividing  only  the  ischiatic  nerve, 
I  divided  the  four  nerves  going  to  one  of  the  posterior  limbs,  of 
many  frogs,  in  whom  the  spinal  cord  was  divided  immediately 
behind  the  roots  of  the  brachial  nerves. 

I  have  found  on  the  separated  limbs  of  these  frogs  : 


71 

1st.  That,  at  first,  the  muscular  irritability  was  greater  in  the 
limb  which  had  been  deprived  of  the  action  of  the  spinal  cord  and 
of  the  brain,  than  in  the  limb,  deprived  only  of  the  action  of  the 
brain. 

2d.  That,  at  a  variable  time  after  the  operation,  the  irritability 
was  at  the  same  degree  in  the  two  limbs. 

3d.  That,  at  last,  the  irritability  became  greater  in  the  limb  only 
deprived  of  the  action  of  the  brain,  than  in  the  other.* 

The  differences  in  the  degree  of  irritability  have  been 
observed  :  1st.  By  the  degree  of  the  contraction  under  the  influence 
of  the  same  excitation;  2d.  By  the  duration  of  irritability. 

I  have  found  that  during  a  time,  varying  much  according  to  sea- 
sons, and  to  many  other  circumstances,  the  muscular  irritability 
increases  in  the  two  posterior  limbs  in  a  frog  operated  upon  as  I 
have  described,  and  that  the  increase  was  more  considerable  in  the 
limb  where  the  nerves  were  divided  than  in  the  other. 

If  we  compare  two  frogs,  one  operated  on  as  before,  and  another 
having  only  had  a  division  of  all  the  nerves  on  one  of  the  pos- 
terior limbs,  we  find,  a  few  days  after  the  operation,  that  in  the 
four  limbs  separated  from  the  body  there  are  great  differences  as 
to  the  degree  and  the  duration  of  muscular  irritability :  1st.  The 
three  paralized  limbs  have  a  greater  irritability  than  the  one  not 
at  all  paralyzed.  From  the  three  paralyzed  limbs  the  two  in 
which  the  nerves  have  been  divided  have  both  the  same  degree 
of  irritability,  and  more  than  the  limb  in  which  there  was  only 
what  Marshall  Hall  calls  a  cerebral  paralysis.  2d.  The  irrita- 
bility has  lasted  longer  in  the  two  limbs  in  which  the  nerves  had 
been  cut,  than  in  the  two  other  limbs.;  and  from  these  two,  that 
in  which  there  was  a  cerebral  paralysis  has  remained  longer 
irritable. 

If  we  examine  the  irritability  in  the  posterior  limbs  of  two 
frogs,  operated  on  as  aforesaid,  for  ten,  twelve,  or  fifteen  days, 
then  we  find  that  it  is  nearly  at  the  same  degree  in  the  three 
paralyzed  limbs,  and  greater  there  than  in  the  non-paralyzed 
limb. 

*  There  is,  in  these  experiments,  a  cause  of  error,  arising  from  the 
existence  on  one  side,  and  the  absence,  or,  at  least,  a  diminution  in  the 
other,  of  the  vital  power  of  the  motor  nerves  ;  but  the  difference  is  trifling 
when  the  nerves  are  divided  very  near  their  entrance  in  the  muscles. 


72 

If  the  comparison  is  made  four  or  five  weeks  after  the  opera- 
tion, then  the  non-paralyzed  limb  has  a  greater  irritability  than 
the  three  paralyzed,  and,  from  these  three,  the  one  deprived  only 
of  the  cerebral  action  has  a  greater  irritability  than  the  two 
others. 

The  same  experiments  made  on  other  animals  than  frogs,  i.  e. 
on  guinea-pigs  and  rabbits,  have  given  like  results.  I  shall  pub- 
lish the  details  of  these  last  experiments  in  a  special  paper,  in 
which  I  intend  to  examine  the  value  of  the  clinical  observations 
of  Marshall  Hall,  R.  B.  Todd,  Duchenne  de  Boulogne,  and 
others.  I  will  merely  state  here,  that  in  many  cases  it  is  almost 
impossible  to  know  what  is  the  difference  in  the  degree  of  mus- 
cular irritability  in  a  paralyzed  limb,  compared  with  a  healthy 
limb,  in  a  living  man  or  animal.  Galvanism  and  strychnine  can- 
not give  us  any  exact  notion  in  this  respect.  I  ought  to  add, 
that  if  we  could  know  what  is  the  relative  degree  of  irritability 
in  a  paralyzed  limb,  we  could  not  make  use  of  that  knowledge 
for  the  diagnosis  of  the  seat  of  the  alteration  producing  the 
paralysis.  On  the  other  side,  we  do  not  want  to  know  what  is 
the  degree  of  irritability  in  order  to  establish  such  a  diagnosis. 
It  will  be,  almost  constantly,  easy  to  know  whether  a  paralysis  is 
a  cerebral  or  a  spinal  one.  The  existence  of  reflex  actions  in 
the  paralyzed  parts,  is  sufficient  to  prove  that  there  is  a  cerebral 
paralysis,  and  the  absence  or  the  slight  degree  of  these  actions 
will  prove  that  there  is  a  spinal  paralysis. 

The  following  conclusions  may  be  drawn  from  the  facts 
above  related,  and  from  others  that  I  have  not  yet  published. 

1st.  The  degree  of  muscular  irritability  in  paralyzed  parts, 
becomes  rapidly  greater  than  in  the  healthy  parts,  but,  after  a 
variable  length  of  time,  it  diminishes,  and,  as  it  is  well  known, 
it  may  disappear. 

2d.  The  muscles  deprived  of  the  action  of  both  the  brain  and 
the  spinal  marrow,  become  rapidly  more  irritable  than  the  mus- 
cles deprived  only  of  the  action  of  the  brain,  but,  after  a  certain 
time,  there  is  also  in  them  a  more  rapid  diminution  of  irritability 
than  in  the  others. 

3d.  It  appears  certain  that  the  muscular  irritability  never 


73 

disappears  completely  in  parts  deprived  only  of  the  cerebral 
action.* 

4th.  In  certain  cases  of  paralysis,  and  more  particularly  of 
the  face,  as  after  the  removal  of  a  large  part  of  the  facial  nerve, 
the  muscular  irritability  may  exist  for  years,  at  least  in  rabbits 
and  other  animals. 

5th.  It  is  very  difficult,  and  sometimes  almost  impossible,  to 
know  the  relative  degree  of  muscular  irritability  in  healthy  parts 
compared  with  paralyzed  parts,  and  such  a  knowledge  could  not 
be  of  a  great  semeiological  value. 

6th.  The  existence  or  the  absence  of  reflex  actions  as  a  means 
of  diagnosis  between  the  cerebral  and  the  spinal  paralysis,  has 
a  much  greater  value  than  the  degree  of  muscular  irrita- 
bility. 

XXII. — ON    THE    INCREASE     OF     ANIMAL     HEAT    AFTER     INJURIES 
OF   THE    NERVOUS    SYSTEM. 

In  another  part  of  this  seriesf  I  have  endeavored  to  prove 
that  the  local  increase  of  temperature  following  the  section  of 
the  sympathetic  nerve,  is  the  result  of  paralysis  of  the  blood- 
vessels. I  will  now  relate  some  other  cases  in  which  a  local 
increase  of  temperature  takes  place  after  various  other  inju- 
ries of  the  nervous  system,  and  apparently  in  consequence  of 
the  same  cause. 

It  was  known,  long  ago,  that  an  injury  to  the  nervous  system 
might  be  followed  by  a  partial  or  even  a  general  elevation  of 
animal  heat.  Sir  B.  Brodie  says,!  Mr.  Chossat  has  published  an 
account  of  some  experiments  on  animals,  in  which  he  found 
that  the  division  of  the  superior  portion  of  the  spinal  cord 
produced  a  remarkable  evolution  of  animal  heat,  so  that  it  was 
raised  much  above  the  natural  standard.  I  have  made  experi- 

*  I  have  had  a  pigeon  on  which  nearly  an  inch  of  the  costal  part  of  the 
spinal  cord  had  been  removed,  and  on  which  the  muscular  irritability  in 
the  posterior  limbs,  and  a  very  great  reflex  power,  have  existed  as  long  as 
I  have  taken  care  of  it,  i.  e.  more  than  twenty-seven  months.  I  ought  to 
say  that  there  has  been  no  re-union  of  the  separated  parts  of  the  spinal 
cord. 

•j-  Medical  Examiner,  August  1853,  p.  489. 

JMedico-Chirurg.  Transactions,  1837.  Vol.  xx.,  p.  132. 


74 

ments  similar  to  those  of  Mr.  Chossat,  and  have  met  with  similar 
results.  I  have  also  seen  several  cases  in  which  an  accidental 
injury  of  the  spinal  cord  has  produced  the  same  effect.  The 
most  remarkable  of  them  was  that  of  a  man  who  was  admitted 
into  St.  George's  Hospital,  in  whom  there  was  a  forcible  separa- 
tion of  the  fifth  and  sixth  cervical  vertebroe,  attended  with  an 
effusion  of  blood  within  the  theca  vertebralis,  and  laceration  of 
the  lower  part  of  the  cervical  portion  of  the  spinal  cord.  Res- 
piration was  performed  by  the  diaphragm  only,  and,  of  course, 
in  a  very  imperfect  manner.  The  patient  died  at  the  end  of 
twenty-two  hours ;  and,  for  some  time  previous  to  his  death, 
he  breathed  at  very  long  intervals,  the  pulse  being  weak  and 
the  countenance  livid.  At  last  there,  were  not  more  than  five 
or  six  inspirations  in  a  minute.  Nevertheless,  when  the  ball 
of  a  thermometer  was  placed  between  the  scrotum  and  the 
thigh,  the  mercury  rose  to  111°  of  Fahrenheit's  scale. 
Immediately  after  death,  the  temperature  was  examined  in  the 
same  manner,  and  found  to  be  still  the  same. 

Brodie  was  mistaken  as  regards  the  experiments  of  Chossat. 
Instead  of  finding  an  increase  in  the  animal  heat  after  the  sec- 
tion of  the  inferior  portion  of  the  spinal  cord,  Chossat  found 
a  considerable  diminution  in  the  temperature  of  dogs.  But  in 
two  cases,  where  the  spinal  cord  was  divided  at  about  the 
level  of  the  last  dorsal  vertebra,  in  dogs,  Chossat*  found  an 
increase  in  the  animal  heat.  In  one  of  these  experiments,  the 
increase  was  from  41°.l  to  41°.5  Cents.,  (105°.98  to  106°.7 
Fahr.)  In  the  other,  the  increase  was  from  41°.l  to  42°. 9 
Cs.,  (105°.98  to  109°.6.) 

Dr.  Macartney!  found  an  increase  in  the  temperature  of 
parts  paralyzed  in  consequence  of  the  division  of  their  nerve. 
II.  Nasse,J  who  made  many  experiments  on  this  subject,  some- 
times observed  an  elevation  in  the  temperature  of  the  pa- 
ralyzed parts  after  the  division  of  the  sciatic  nerve,  or  after 
the  partial  destruction  of  the  spinal  cord. 

*  Mem.  sur  P  influence  du  eyst.  nerv.  sur  la  chal.  anim.     These  de  Paris. 
No.  120.— 1820,  p.  35.     Exps.  xxiii  and  xxiv. 
•j-  Treatise  on  Inflammation,  1838,  p.  13. 
j  Yuterstirchungor  zur  Physiol.  und  Pathol.,  1839,  v.  ii.,  p.  190. 


75 

In  more  than  twenty  experiments,  I  only  once  found  an 
increase  in  the  temperature  of  the  leg  of  a  guinea-pig,  after  the 
section  of  the  sciatic  nerve.  This  increase  lasted  about  two 
or  three  days  after  the  operation,  and  it  was  of  two  degrees  Fahr. 

After  a  complete  transversal  section  of  the  spinal  cord  in  the 
lumbar  region,  in  birds  and  mammals,  I  found,  repeatedly, 
an  increase  of  one,  two  or  three  degrees  Fahr.  in  the  temperature 
of  the  paralyzed  parts.  I  ascertained  that  it  is  not  in  conse- 
quence of  an  increase  of  the  general  temperature  of  the  animal 
that  such  an  increase  exists.  It  is  to  be  found  only  in  the 
paralyzed  parts. 

I  never  found  any  increase  of  temperature  after  a  complete 
transversal  section  of  the  spinal  cord,  either  in  the  cervical  or  in 
the  dorsal  region. 

After  a  section  of  a  lateral  half  of  the  spinal  cord,  at  the 
level  of  one  of  the  three  or  four  last  dorsal  vertebrae,  I  have 
almost  constantly  found  an  increase  in  the  temperature  of 
the  posterior  limb  on  the  side  of  the  section.  The  elevation 
varied  from  one  to  four  degrees  Fahr.  On  the  contrary,  there 
was  a  diminution  of  from  one  to  five  degrees  Fabr.  in  the 
temperature  of  the  other  leg.  In  some  cases,  in  consequence  of 
the  increase  of  temperature  on  one  side  and  its  diminution  on 
the  other  side,  I  found  a  difference  of  six  or  seven  degrees 
Fahr.  in  the  temperature  of  the  two  limbs.  It  is  very  remark- 
able that,  together  with  the  increase  of  temperature  in  one 
limb,  there  is  an  augmentation  of  sensibility,  and  with  the  di- 
minution of  temperature  in  the  other  limb,  there  is  also  a  dimi- 
nution of  sensibility. 

Sinca  the  publication  of  the  results  of  my  experiments  on  the 
sympathetic  nerve,  I  have  performed  them  many  other  times, 
and  I  have  found  that  the  result  is  not  so  constant  as  Dr.  A. 
Barnard  and  myself  had  admitted.  In  some  rabbits  there  was 
no  decided  increase  in  the  vascularization  and  in  the  tempe- 
rature of  the  face.  I  ought  to  say  that,  in  these  cases,  the  two 
ears  were  already  warm,  and  very  vascular  before  the  operation. 
I  have  found,  also,  that  generally  in  very  cold  weather  the  ex- 
tremity of  the  ear  of  rabbits,  on  the  side  of  the  section  of  the 
sympathetic  nerve,  remains  cold. 

From  my  experiments  and  from  the  observations  and  experi- 


76 

ments  of  Brodie,  Chossat,  H.  Nasse  and  Macartney,  it  results 
that  the  following  opinion  of  Dr.  Cl.  Bernard  is  incorrect.  He 
says :  "  It  is  known  that  injuries  of  the  cerebro-spinal  ner- 
vous system  constantly  produce  a  total  or  a  partial  diminu- 
tion in  the  temperature  of  animals,  either  when  a  nerve  has  been 
divided  or  when  the  injury  is  made  on  the  nervous  centres."* 
He  says  also  that  an  injury  of  the  sympathetic  nerve  produces 
a  very  rapid  increase  of  temperature ;  so  that  the  sympathetic 
nerve  and  the  cerebro-spinal  nervous  system  are  considered  by 
Dr.  Bernard  as  completely  different,  one  from  the  other,  as  to 
the  influence  on  animal  heat  when  they  are  injured.  The  one 
should  increase  and  the  other  diminish  animal  heat. 

The  truth  is  that  these  two  effects — increase  and  diminution — 
may  exist  after  an  injury  of  either  the  sympathetic  or  the  cere- 
bro-spinal nervous  system  ;f  and,  in  both  cases,  the  increase  may 
exist,  at  first,  and  be  followed  by  a  diminution. 

Before  pointing  out  the  co-existence  of  certain  facts  with  the 
increase  or  diminution  of  animal  heat,  I  think  it  necessary  to  es- 
tablish a  distinction  between  the  cases  of  increase  of  animal  heat 
after  injuries  of  the  nervous  system. 

In  some  cases  (as  those  related  by  Brodie)  there  has  been  an 
increase  of  temperature  above  the  natural  standard  of  animal 
heat.  These  are  very  extraordinary  and  very  rare  cases,  and 
it  is  not  my  intention  to  attempt  to  explain  them  here.  In  the 
cases,  the  degree  of  temperature,  although  increased  in  some  other 
paralyzed  parts,  has  not  been  above  the  normal  degree  of  blood 
heat.  This  is  the  only  kind  of  increase  of  animal  heat  that  I 
have  observed,  and  this  I  will  attempt  to  explain. 

I  have  found  that, — ceteris  paribus, — the  more  the  arteries 
and  capillaries  are  dilated,  the  higher  is  the  degree  of  tempera- 
ture. This  law  is  proved  by  the  following  facts : 

1st.  In  all  the  cases  of  paralysis  (from  whatever  cause) 
where  I  have  found  a  diminution  in  the  degree  of  temperature 
of  a  paralyzed  part,  the  arteries  and  capillaries  were  evidently 
much  contracted. 

2d.  In  the  cases  where  the  temperature  was  normal,  the  blood- 
vessels were  of  their  natural  size. 

*Gaz.  Medic,  de  Paris,  Vol.  7,  No.  14,  p,  227. 
t  Vide  :  Chossat,  loco  clt.:  pp.  41-46. 


77 

3d.  In  the  cases  where  the  temperature  was  increased,  I  have 
constantly  found  the  arteries  and  capillaries  enlarged. 

4th.  In  some  cases,  I  have  found  the  same  changes  occurring 
in  the  temperature  and  in  the  blood-vessels.  The  temperature 
at  first  was  greater  than  usual  and  the  blood-vessels  dilated  ; 
afterwards  both  the  temperature  and  blood-vessels  became  natu- 
ral ;  and,  at  last,  the  temperature  becoming  lower  than  usual, 
the  size  of  the  blood-vessels  became  smaller. 

I  need  not  say  that  the  changes  occurring  in  paralyzed 
parts  in  accordance  with  the  size  of  the  blood-vessels  were  the 
results  of  the  differences  in  the  amount  of  blood  passing  in  these 
parts. 

Now,  it  will  be  asked  how,  in  certain  cases  of  palsy,  the  size 
of  the  blood-vessels  is  larger  than  usual,  and  smaller  in  other 
cases.  I  .cannot  explain  how  it  is  so,  but  I  can  assert  that  it  is 
a  fact. 

From  the  facts  and  reasonings  related  in  this  article,  I  draw 
the  following  conclusions  : 

1st.  An  injury  of  the  nervous  system  may  produce  in  the 
parts,  which  then  become  paralyzed,  either  an  increase  or  dimi- 
nution of  temperature. 

2d.  The  sympathetic  nerve  and  the  cerebro-spinal  nervous 
system  appear  not  to  be  different  one  from  the  other,  in  this 
respect. 

3d.  The  degree  of  temperature  of  paralyzed  parts  depends  on 
the  quantity  of  blood  they  receive  ;  and  this  quantity  varies  ac- 
cording to  the  size  of  the  arteries  and  capillaries  of  these  parts. 

4th.  It  is  a  fact,  hitherto  unexplained,  that  the  arteries  and 
capillaries  may  be  either  dilated,  normal,  or  contracted  in  para- 
lyzed parts. 

XXIII CAUSE    OF   THE    STOPPING   OF    THE  HEART'S    MOVEMENTS, 

PRODUCED  BY   AN  EXCITATION  OF  THE  MEDULLA    OBLONGATA  OR 
THE  PAR   VAGUM. 

E.  II.  and  E.  Weber  have  discovered  a  singular  fact,  hitherto 
unexplained.  When  the  par  vagum  or  the  medulla  oblongata  is 
excited  by  a  powerful  electro-magnetic  current,  in  a  living 
animal,  the  movements  of  the  heart  are  suddenly  stopped.  This 


78 

should  be  what  is  known  for  all  motor  nerves  and  muscles,  if  the 
cessation  of  the  movements  of  the  heart  was  the  result  of  a  per- 
manent contraction.  But  the  heart  is  not  at  all  contracted,  and, 
on  the  contrary,  it  remains  perfectly  placid. 

This  is  entirely  different  from  what  we  know  to  be  the  case 
for  other  muscles. 

I  have  found  that  a  violent  mechanical  excitation  of  the  me- 
dulla oblongata  produces  also  the  same  stopping  of  the  heart's 
action. 

Is  the  heart  in  a  state  of  rest  in  consequence  of  a  loss  of  its 
irritability  or  of  an  interruption  of  the  excitation  necessary  to 
its  action  ?  The  following  fact  proves  that  this  second  opinion 
is  the  right  one.  When  the  heart  is  stopped,  every  direct  exci- 
tation upon  it  produces  some  beatings,  and  then,  its  irritability 
appears  to  be  entire.  The  stopping,  consequently,  depends  on 
the  absence  of  excitation. 

The  cause  exciting  the  heart  to  beat  is  in  the  blood  contained 
in  the  capillaries  of  this  organ,  as  I  will  try  to  prove  in  another 
article.  Now,  if  we  suppose  that  the  galvanization  of  the  par 
vagum  produces  a  complete  constriction  of  the  capillaries  of  the 
heart,  it  is  easy  to  understand  why  the  heart  is  stopped:  it  is 
because  the  excitation  cannot  take  place  on  account  of  the  ex- 
pulsion of  the  blood  from  the  capillaries. 

It  will  be  asked  on  what  ground  we  base  the  supposition  that 
the  capillaries  are  so  contracted  that  they  prevent  entirely,  or 
nearly  so,  the  passage  of  the  blood.  I  will  answer  : 

1st.  That  it  is  known  that  a  galvanization  of  certain  nerves 
(and  I  have  discovered  that  it  is  so  with  the  capillaries  of  the  face 
and  ear  when  the  sympathetic  nerve  is  galvanized)  may  pro- 
duce a  considerable  constriction  of  capillaries. 

2d.  That  it  is  known  that  the  nerves  of  the  heart  are  distri- 
buted much  more  to  its  blood-vessels  than  to  its  muscular  tissue. 

3d.  That,  by  our  supposition,  we  place  the  fact  of  the  stopping  of 
the  heart's  movements  among  the  well  known  facts,  that  an  excita- 
tion of  a  molar  nerve  produces  a  contraction  of  the  muscles  to 
which  it  is  distributed  ;  and,  therefore,  we  are  not  obliged  to  admit 
that  an  excitation  of  a  nerve  is  able  to  produce  directly  either  a 
contraction  of  or  the  cessation  of  existing  contractions. 

There  is  a  practical  consequence  to  be  drawn  from  the  fact  that 


79 

in  the  case  of  an  excitation  of  the  medulla  oblongata,  the  stopping 
of  the  heart  is  not  produced  by  a  loss  of  irritability  of  this  organ. 

Many  cases  of  syncope  are  produced  by  a  stopping  of  the 
heart's  movements  in  consequence  of  the  influence  of  an  emotion 
on  the  medulla  oblongata.  In  these  cases  it  would  be  of 
very  great  importance  to  excite  directly  the  beatings  of  the  heart, 
either  by  compression  of  the  chest  or  by  an  application  of  gal- 
vanism. 

We  ought  to  say  that  galvanism  applied  directly  to  the  heart 
increases  its  beatings  instead  of  diminishing  them. 

XXIV. — ON  A  SINGULAR  DISTURBANCE  IN  THE  VOLUNTARY  MOVE- 
MENTS, APPARENTLY  PRODUCED  BY  AN  ACTION  OP  ATMOSPHERIC 
AIR  ON  THE  GRAY  MATTER  OF  THE  SPINAL  CORD,  IN  BIRDS. 

Some  years  ago  I  discovered  that  after  the  removal  of  a  large 
quantity  of  the  gray  matter  that  exists  in  birds,  on  the  posterior 
surface  of  the  spinal  cord,  in  the  lumbar  region,  a  great  disturb- 
ance took  place  in  the  voluntary  movements.  I  attributed  this 
disturbance  to  the  loss  of  gray  matter.  I  have  found,  three 
or  four  months  since,  that  the  same  disturbance  existed  in  the 
voluntary  movements  after  I  had  merely  laid  bare  the  gray 
matter,  and  immediately  after  it  had  been  exposed  to  the  action 
of  air. 

I  am  perfectly  satisfied  that  it  is  not  in  consequence  of  a 
mechanical  excitation  of  the  spinal  cord,  accidentally  produced 
during  the  operation  of  the  removal  of  the  bones  and  membranes, 
that  this  disorder  takes  place. 

When  the  spinal  cord  is  laid  bare  elsewhere  than  in  the  region 
of  the  lumbar  enlargement — that  is,  in  any  place  where  the  white 
substance  covers  completely  the  gray  matter — there  is  no  disturb- 
ance produced  in  the  voluntary  movements. 

That  disturbance  very  much  resembles  the  so-called  titubn- 
tion  which  exists  after  either  the  removal  of  the  cerebellum  or 
the  section  of  muscles  of  the  posterior  part  of  the  neck.  At 
each  movement  of  progression,  the  animal  tends  to  fall  either 
forwards,  backwards,  or  laterally.  It  does  not  fall  completely, 
but  is  obliged,  in  order  to  avoid  falling,  to  make  use  of  its  wings, 
its  tail  and  its  beak. 


80 


XXV. — ON   THE   TREATMENT   OF   EPILEPSY. 

I  have  made  numerous  experiments  with  regard  to  the  treatment 
of  this  dreadful  affection,  and  I  intend  to  publish  them,  in  extenso, 
when  some  points  that  are  still  obscure  have  become  clear  to  my 
mind.  Here  I  will  merely  relate  some  of  the  most  important  results 
of  my  researches.  As  I  have  had  the  opportunity  during  the  last 
three  or  four  years  of  observing  every  day  a  great  many  animals 
(more  than  a  hundred)  which  had  a  convulsive  affection  resembling 
epilepsy  very  much,  I  have  been  able  to  discover  some  very  in- 
teresting facts,  among  which  are  the  following  : 

1st.  For  each  epileptic  animal,  the  number  of  fits,  in  a  given 
time,  is  generally  in  a  direct  proportion  with  the  quantity  of  food 
taken. 

2d.  There  is  an  inverse  proportion  between  the  amount  of  exer- 
cise and  the  number  of  fits. 

3d.  Cauterisation  of  the  mucous  membrane  of  the  larynx  is 
able  either  to  cure  or  to  relieve  these  epileptic  animals. 

The  convulsive  affection  existing  in  almost  all  these  animals 
was  the  consequence  of  a  transversal  section  of  a  lateral  half  of 
the  spinal  cord,  in  the  dorsal  or  in  the  lumbar  region. 

I  have  already  published  the  results  of  my  experiments  on 
epilepsy,  in  rny  lectures  before  large  classes  of  Physicians  and 
Medical  students,  both  in  France  in  1851  and  in  this  country  in 
1852. 

These  results  are  in  perfect  accordance  with  the  views  of  Dr. 
Marshall  Hall  in  relation  to  epilepsy.  As  the  views  of  this  emi- 
nent biologist  are  generally  known,  I  need  not  expose  them,  and 
I  will  merely  remind  my  readers  of  the  three  following  points  : 

1st.  The  first  muscles  that  contract  spasmodically  in  almost 
all,  if  not  in  all,  the  cases  of  epileptic  fits,  are  those  of  the  larynx 
and  the  neck  :  2d,  spasm  of  the  glottis  taking  place  then, 
produces  suffocation,  in  consequence  of  which  convulsions  are 
produced  in  the  trunk  and  the  limbs;  3d,  tracheotomy  may  pre- 
vent these  convulsions  by  preventing  suffocation,  and  it  is  known 
that  in  some  cases  tracheotomy  has  cured  epilepsy. 

It  has  been  objected  to  Marshall  Hall  that  in  cases  of  poison- 
ing by  strychnine,  convulsions  take  place  even  when  a  tracheal 
tube  renders  respiration  perfectly  free.  This  objection  has  no 


81 

value,  because  the  state  of  the  spinal  cord  in  epileptics  is  not 
the  same  as  in  men  or  animals  poisoned  by  strychnine.  Cer- 
tainly the  excitability  of  the  spinal  cord  is  greater  in  epileptics 
than  in  healthy  persons,  but  the  degree  of  excitability  of  that 
nervous  centre  is  much  greater  in  persons  poisoned  by  strych- 
nine than  in  epileptics ;  and,  therefore,  it  is  easy  to  understand 
that  certain  excitations  are  able  to  produce  general  convulsions 
in  one  case  and  not  in  the  other. 

If  we  give  a  very  slight  dose  of  strychnine  to  an  animal,  so  as 
not  to  poison  it,  but  merely  to  increase  slightly  the  excitability  of 
the  spinal  cord,  there  are  no  convulsions  when  we  touch  or 
pinch  or  burn  the  skin,  but  if  we  prevent  breathing  for  a  few 
seconds  only,  general  convulsions  take  place,  exactly  as  in  epi- 
leptic men  or  animals. 

It  has  been  said  also,  in  opposition  to  Marshall  Hall,  that  a 
spasm  of  the  glottis  of  the  severest  kind  occurs  in  cases  of  hoop- 
ing cough,  of  spasmodic  croup  and  even  of  apoplexy,  without  the 
occurrence  of  any  other  convulsions.  The  answer  to  this  objec- 
tion is,  that  in  epilepsy  the  spinal  cord  is  more  excitable  than  in 
these  other  diseases,  so  that  the  same  kind  of  excitation  does  not 
produce  the  same  effects. 

A  great  many  facts,  that  I  will  publish  elsewhere,  prove  that 
black  blood,  very  probably  by  its  carbonic  acid,  is  an  excitant  of 
the  spinal  cord  and  of  the  medulla  oblongata.  When,  as  is 
the  case  in  asphyxia,  the  blood  is  not  oxygenated  and  deprived  of 
the  carbonic  acid  constantly  produced  in  it,  or  received  by  it 
from  different  tissues,  then  tne  excitation  made  on  these  nervous 
centres  becomes  so  powerful  that  convulsions  are  produced.  This 
is  found  in  men  and  animals,  even  in  perfect  health.  If  the  as- 
phyxia is  incomplete,  convulsions  are  not  produced,  unless  the 
excitability  of  the  spinal  cord  is  greater  than  usual,  and  this  is 
the  case  in  epileptics. 

In  November,  1851,  at  the  Ecole  Pratique,  of  Paris,  I  pub- 
lished for  the  first  time,  before  a  class  of  about  forty  young 
Physicians  and  Medical  students,  the  results  of  my  experiments 
as  regards  the  cauterization  of  the  larynx  in  epilepsy.  About 
eight  months  after,  Dr.  Eben  Watson  published  a  paper*  in 

*  Kemarks  on  Dr.  M.  Hall's  theory  of  the  relation  of  Laryngysmus  to 
Epilepsy.  In  London  Journal  of  Medicine,  July,  1852,  pp.  641-43. 


82 

which  he  says  :  "  The  treatment  I  would  now  propose  instead  of 
tracheotomy  is  simply  the  application  of  a  solution  of  nitrate  of 
silver,  varying  in  strength  with  the.  requirements  of  the  case,  to 
the  glottis  of  the  patient,  with  the  view  of  diminishing  the 
nervous  excitability  of  the  part  in  question.  A  similar  treat- 
ment has  been  found  by  me  remarkably  successful  in  alleviating 
and  removing,  in  a  short  time,  the  susceptibility  of  the  patient 
to  laryngysmus,  in  cases  of  hooping  cough,  and  of  spasmodic 
'croup  (laryngysmus  stridulusj)  nor  can  I  see  any  reason  why  a 
similar  result  should  not  ensue  in  chronic  cases  of  epilepsy." 

The  reasons  given  by  Dr.  E.  Watson  are  partly  the  same  by 
which  I  had  been  led  long  before  him  to  perform  the  operation 
he  suggests.  But  I  had  also  some  other  reasons.  It  is  perfectly 
known,  in  the  actual  state  of  Medical  Science,  that  the  great- 
est changes  may  be  produced  in  the  nervous  centres,  as  well  as 
in  the  nerves,  by  a  very  strong  excitation  of  the  termination  of 
the  nervous  fibres  in  the  skin  or  the  mucous  membranes.  On 
this  principle  are  founded  many  modes  of  treatment  of  some  dis- 
eases of  the  spinal  cord  and  of  neuralgia.  The  application  of 
caustics,  blisters,  cupping,  hot  iron,  etc.,  is  based  on  this  princi- 
ple. In  accordance  with  it  I  am  inclined  to  believe  that  epilepsy 
might  be  cured  by  a  mere  application  of  a  hot  iron  to  the  skin 
of  the  neck  ;  at  least  I  have  had  two  guinea-pigs  cured  after  such 
an  application,  repeated  three  or  four  times. 

The  operation  of  tracheotomy  proposed  by  Marshall  Hall  has 
proved  successful  in  some  cases.  But  it  is  a  dangerous  operation, 
and  if  it  is  proved  that  another  one  much  slighter  can  produce 
the  same  good  effects,  it  ought  not  to  be  practised. 

That  other  operation  is  the  cauterization  of  the  larynx ;  it 
prevents  the  closure  of  the  glottis,  and  thus  is  able  to  cure 
or  to  relieve  epileptic  patients  as  well  as  it  cures  some  other 
diseases.  Every  learned  physician  knows  that  it  is  sufficient  to 
cauterize  the  larynx  once  or  twice  to  cure  hooping  cough  in 
almost  every  case. 

When  the  cause  of  the  epileptic  fits  is  excessive,  and  when  the 
spinal  cord  is  very  excitable,  to  allow  free  breathing  merely 
will  not  be  sufficient  to  prevent  the  general  convulsions.  But 
their  violence,  if  respiration  is  free,  will  be  deprived  of  all  the 
effect  that  would  be  produced  by  the  excitation  of  black  blood 
if  breathing  did  not  take  place. 


83 

The  distinction  made  between  organic  and  inorganic  epilepsy  has 
not  the  importance  that  some  writers  seem  to  admit.  There 
are  alterations  in  the  nervous  system  in  both  cases,  and  the  only 
difference  is  that  these  alterations  can  be  easily  seen  with  the 
naked  eye  in  one  case  and  not  in  the  other.  I  ought  to  point 
out  that  the  cases  of  epilepsy  in  animals,  which  I  have  cured, 
were  cases  of  organic  epilepsy.  These  animals  have  been  cured, 
although  the  apparent  and  primitive  cause  of  the  disease,  i.  e.  a 
section  of  a  lateral  half  of  the  spinal  cord,  continued  to  exist. 

The  cauterisation  of  the  larynx  on  these  animals  was  made 
every  day,  or  every  other  day,  and  sometimes  during  two  or  three 
months.  In  some  cases,  the  relief  having  been  immediate,  the 
cauterisation  was  made  only  twice  a  week.  One  of  the 
animals  experimented  on  was  cured  after  three  or  four  cau- 
terisations ;  but  the  number  of  cauterisations  necessary  has  been 
generally  very  much  greater.  When  I  left  France  in  February, 
1852,  I  had  cured  about  a  third  of  the  animals  treated  by  this 
method ;  and  all  the  others,  except  two  or  three,  had  been  very 
much  relieved,  and  certainly  many  of  them  would  have  been  cured 
if  the  treatment  had  been  prolonged. 

I  knew  that  an  animal  was  cured,  not  only  by  the  absence  of 
spontaneous  fits,  but  when  I  could  not  produce  a  fit  by  giving 
great  pain.  I  had  found  that  on  any  epileptic  animal,  except  im- 
mediately after  a  paroxysm,  I  could  very  easily  produce  a  fit  by  ex- 
citing pain  and  more  particularly  by  pinching  or  burning  the  skin 
of  the  face  or  neck.  So  that  I  am  authorised  to  believe  that  when 
a  fit  was  not  produced  by  pinching  or  burning  the  face,  it  was 
because  epilepsy  had  ceased  to  exist. 

Some  physicians  in  this  country  have  already  tried  on  man 
the  mode  of  treatment  that  I  have  found  so  successful  on  animals. 
From  what  I  know  of  the  results  of  their  attempt,  it  seems  to 
me  that  man  is  like  animals  in  this  respect.  There  has  not  been 
yet  a  complete  curation :  but,  except  in  one  case,  there  has  been 
a  very  considerable  diminution  in  the  frequency  and  the  intensity 
of  the  fits. 

As  physicians  who  have  to  treat  epileptics,  have  not  to 
make  experiments,  but  to  cure  by  making  use  of  all  the  best 
means  together,  I  think  that  the  treatment  of  epilepsy  ought 


84 

not  to  consist  merely  of  the  cauterisation  of  the  larynx.  The 
plan  of  treatment  I  should  suggest  is  the  following : 

1st.  A  cauterisation  of  the  larynx  with  a  strong  solution  of 
nitrate  of  silver,  (at  least  60  grains  to  the  ounce,)  every  day,  for 
at  least  five  or  six  weeks, 

2d.  A  cauterisation  of  the  skin  of  the  neck  over  the  spine, 
with  a  hot  iron,  once  a  fortnight,  for  about  two  or  three  months. 

3d.  Exercise  and  gymnastics. 

4th.  Make  use  of  oxide  of  zinc  or  ammoniated  copper,  remedies 
which  a  very  respectable  physician  of  Geneva,  ('Switzerland,) 
Dr.  Herpin,  has  found  successful  in  many  cases,  when  their  dose 
has  been  considerable.* 

5th.  If  in  a  fit  of  epilepsy  the  suffocation  is  very  considerable, 
the  operation  of  tracheotomy  ought  then  to  be  performed  imme- 
diately. 

XXVI, — CUKE   OF   EPILEPSY  BY  SECTION  OF  A  NERVE. 

It  is  a  well  known  fact  that  epilepsy  may  be  produced  by  injury 
to  a  nerve.  Dr.  John  Cooke,  in  his  Treatise  on  Nervous  Diseases, 
says  on  this  subject :  "  From  the  writings  of  Forestus,  Van  Swie- 
ten  and  Tissot,  it  appears  that  injury  done  to  the  nerves,  or  that 
a  morbid  state  of  them,  has  in  many  instances  given  occasion  to 
epilepsy.  In  the  Edinburgh  Medical  Essays  and  Olserv.,  a 
case  is  related  of  a  violent  epilepsy,  which  frequently  occurred, 
which  was  produced  by  a  hard  cartilaginous  substance,  of  the 
size  of  a  large  pea,  situated  upon  a  nerve.  That  this  was  the 
cause  was  evident,  as  the  disease  ceased  on  the  extirpation  of  the 
tumor.  In  the  same  we  have  an  account  of  epilepsy  depending 
upon  a  calculus  of  an  irregular  figure,  about  the  size  of  a  nut, 
pressing  on  a  branch  of  the  sciatic  nerve ;  and  another  in  which 
the  par  vagum  was  compressed  by  a  concretion  of  a  similar 
kind."  Darwin,  in  his  Zoonomia,  says,  "I  once  saw  a  child 
about  ten  years  old,  who  frequently  fell  down  in  convulsions,  as 
she  was  running  about  in  play.  On  examining,  a  wart  was 
found  on  one  ankle,  which  was  ragged  and  inflamed,  which  was 
cut  off,  and  the  fits  never  recurred." 

*  See  his  admirable  work:  Du  Pronostic  et  du  Trailement  de  V Epilepsie. 
Paris,  1852.  Ouvrage  couronne  par  PInstitut  de  France. 


85 

Van  Swieten  relates  a  case  of  curation  of  epilepsy  by  the  ex- 
tirpation of  a  hard  cartilaginous  body,  somewhat  larger  than  a 
pea,  situated  on  a  nerve  of  the  leg. 

A  case  is  related  in  the  Medical  and  Physical  Journal,  (vol. 
x.  p.  52,)  in  which  a  cure  of  epilepsy  was  effected  by  the 
application  of  caustic  to  the  nerve  which  accompanies  the  vena 
saphena. 

Many  other  analogous  cases  are  on  record.  Jacques  Carron, 
(Recueil periodique  de  la  Soc.  de  Medecine  de  Paris,  t.  xviii.  p. 
422,)  cured  a  child  by  the  extirpation  of  a  small  sebaceous 
tumor  which  existed  on  one  of  the  fingers.  Portal,  (Observations 
sur  Tepilepsie,  Paris,  1827,  p.  159,)  cites  a  case  observed  by 
Fabos,  in  which  the  fits  were  preceded  by  a  pain  in  one  of  the 
fingers.  During  a  violent  fit  Fabos  put  a  ligature  around  the 
radial  nerve,  and  the  patient  was  completely  cured.  Portal 
(Anatomic  Medicale,  vol.  iv.  p.  247,)  relates  that  one  of  his 
pupils,  Mr.  Leduc,  cured  an  epileptic  by  the  extirpation  of 
a  hard  tumor  which  was  on  one  of  the  fingers.  Joseph  Frank 
cured  by  castration  a  patient  in  whom  epilepsy  had  appeared 
after  an  injury  to  the  scrotum.  Henricus  ab  Heer,  cited  by 
Sennert,  (Opera  omnia,  vol.  ii.  p.  489,)  having  observed  that 
during  her  fits,  a  girl  used  to  rub  her  two  big  toes,  cured  her 
by  the  application  of  caustic  to  these  toes.  Similar  cases  have 
been  related  by  Alexander,  of  Tralles,  and  by  Wepfer. 

I  have  cured  a  guinea-pig  of  a  very  violent  convulsive  affec- 
tion, much  resembling  epilepsy,  by  a  section  of  the  sciatic  nerve. 
This  animal  had  been  bitten  by  another  on  the  toes  of  one  of  the 
posterior  limbs.  A  considerable  slough  appeared  on  the  wounded 
part,  and  after  two  or  three  weeks  fits  appeared,  and  the  animal 
shortly  afterwards  had  many  very  violent  fits  every  day.  I  laid 
bare  the  sciatic  nerve  and  cut  it  transversely.  After  this  opera- 
tion I  kept  the  animal  many  months,  and  never  saw  it  have  a 
fit.  From  this  fact,  and  from  those  observed  by  many  physi- 
cians above  related,  it  appears  clearly  that  in  cases  of 
epilepsy  it  is  necessary  to  examine  if  there  is  no  injury  whatever 
to  some  nerve,  and  more  particularly  when  the  aura  epileptica 
exists.  If  there  is  such  an  injury,  the  treatment  ought  to  be 
either  the  section  of  the  injured  nerve  or  the  removal  of  the 
tumor,  if  there  is  one,  and  sometimes  the  application  of  a  caustic 
or  a  blister. 


86 


XXVII. — LAWS  OF  THE  DYNAMICAL  ACTIONS  IN  MAN  AND  ANIMALS.* 

The  following  laws  are  based  upon  a  very  considerable  number 
of  facts  which  I  have  observed  or  found  on  record  in  many  books, 
pamphlets  and  journals.  I  have  collected  these  facts  and  I  in- 
tend to  publish  them  in  a  special  paper. 

I  ought  to  say  that  many  Physiologists,  and  more  particularly 
Fontana,  Delaroche,  Adamucci,  Broussais,  Buchez,  Re'veille'- 
Parise,  J.  Mueller,  J.  Paget  and  Carpenter,  have  pointed  out  the 
existence  of  some  parts  of  some  of  these  laws. 

1.  Nervous  actions,  muscular   contraction,  contraction  of  the 
cellular  tissue,  the,  discharge  of  the  electrical  apparatus  of  some 
fishes,  the  galvanic  current  of  certain  organs,  the  galvanic  dis- 
charge which  accompanies  the  muscular  contraction,  and  probably 
also  the  phosphorescence  of  certain  animals  and  the  ciliary  move- 
ments, are  phenomena  which  cannot  exist  without  being  attended 
with  an  organic  waste  which  nutrition  alone  can  provide  for. 

2.  The  faculty  of  originating  these  phenomena  has  a  tendency 
to  increase  in  direct  ratio  to  the  rapidity  of  the  circulation  of 
blood,  to  its  abundance,  and  to  the  amount  of  its  nutritive  ma- 
terials, both  general  and  special. 

3.  During  rest,  i.  e.  at  the  time  of  the  non-existence  of  these 
phenomena,  the  tendency  of  such  a  faculty  towards  augmenta- 
tion   meeting  with  no  obstacle,   augmentation    actually   takes 
place. 

4.  The  increase  is  much  more  rapidly  effected  when  an  action 
has  just  been  performed,  than  it  is  after  a  prolonged  rest. 

5.  Nutrition  becoming  altered  in  the  tissues  which  remain  in- 
active for  a  long  time,  the  faculty  of  producing  the  above-men- 
tioned   phenomena    diminishes    by   degrees,   and   even   finally 
disappears  when  the  structure  of  the   tissues  has  been  deeply 
modified. 

6.  The  faculty  of  originating  these  phenomena  increases  in 
direct  ratio  with  the   length  of  the  rest,  within  certain  limits ; 
and  when  the  latter  are  overleaped,  there  is  a  period  when  no 
change  takes  place ;  but  afterwards  the  faculty  decreases,  on 
the  contrary,  in  direct  ratio  with  the  length  of  the  rest. 

*  I  ought  to  say  that  these  laws  and  the  facts  upon  -which  they  are  esta- 
blished, have  been  the  subject  of  many  communications  that  I  have  made  to 
the  Societc  de  Biologic,  at  Paris,  in  the  year  1848. 


87 

7.  For  many  tissues  which  produce  these  phenomena  a  com- 
plete rest  is  scarcely  possible.      The  phenomena  take  place,  in 
appearance,  spontaneously,  and  with   as   much  energy  as  the 
temperature  is  higher. 

8.  The  faculty  of  producing  these  phenomena  decreases  at  the 
time  they  are  going  on,  in  proportion  to  their   intensity  and 
duration,  and  in  inverse  ratio   to   the  nutritive  reparation  which 
simultaneously  takes  place. 

9.  Reparation  thus  incessantly  supplying  for  expenditure,  it 
is  not  possible,  with  regard  to  most  of  these  phenomena,  and  as 
long  as  circulation  goes  on,  to  destroy  entirely  the  faculty  of 
originating  them ;  or  rather,  as  soon  as  we  have  succeeded  in 
destroying  that  faculty,  it  is  reproduced  by  nutrition. 

10.  Expenditure  dependent  upon  action,  being  followed  by  a 
great  activity  in  the  nutrition,  it  happens  that,  if  the  action  be 
frequently  renewed,  there  is  an  excess  of  nutrition  and  a  consi- 
derable increase  of  the  faculty  of  acting. 

11.  When  the  faculty  of  acting  has  been  increased  in  virtue 
of  the  preceding  reasons,  within  a  certain  limit,  an  equilibrium 
exists  between  the  expenditure  and  the  reparation,  and  the  in- 
crease no  longer  takes  place. 

12.  As  it  is  possible  for  nutrition  to  take  place  in  the  tissues, 
although  the  nutritive  fluid  is  not  actually  circulating  in  them, 
and  provided  that  a  certain   amount  of  it  exists  in  them,  the 
faculty  of  acting  may  be  increased  in  parts  where  circulation  is 
stopped. 

13.  Although  circulation  and  consequently  reparation,  are 
more  active  in  summer  than  in  winter  time,  at  least   in  cold- 
blooded animals,  the  faculty  of  acting  becomes  more  consider- 
able in  winter  than   in  summer  time,  because  the  spontaneous 
expenditures  abovementioned,  and  those  due  to  external  stimuli, 
or  dependent  upon  the  will,  are  by  far  less  considerable. 

All  the  preceding  laws  may  be  summed  up  in  the  following : 
The  intensity  of  the  faculty  which  animal  tissues  possess,  of 
producing  the  vital  phenomena,  seems  to  be  in  a  direct  ratio  to 
the  intensity  and  duration  of  the  nutritive  reparation,  and  in  an 
inverse  ratio  to  the  intensity  and  duration  of  the  existence  of 
these  phenomena. 


88 


XXVIII. — INFLUENCE    OF    RED   BLOOD    ON  MUSCLES   AND   NERVES 
DEPRIVED    OF   THEIR  VITAL   PROPERTIES. 

James  Phillips  Kay*  has  found  that  blood,  injected  into  limbs 
of  dead  animals,  just  after  irritability  has  disappeared,  is  capable 
of  regenerating  this  vital  property.  I  have  gone  much  farther,  and 
have  discovered  that  blood  is  able  to  regenerate  the  vital  proper- 
ties of  nerves  and  muscles,  even  in  limbs  which  have  lost  their 
irritability  and  have  been  rigid  for  several  hours.  I  have  ob- 
tained this  result  from  the  following  experiments  : 

1st.  On  the  body  of  a  rabbit,  in  which  cadaveric  rigidity  had 
already  existed  for  10,  20,  and  in  one  case,  33  minutes,  I 
divided  the  aorta  and  the  vena  cava  in  the  abdomen,  immediately 
above  the  bifurcation  of  these  vessels.  By  means  of  small  tubes, 
a  communication  was  established  between  their  peripheric  ex- 
tremity  and  the  central  extremity  of  the  corresponding  vessels 
divided  in  a  living  rabbit.  The  blood  of  this  living  animal 
circulated  immediately  in  the  posterior  limbs  of  the  dead  one. 
After  about  six,  eight  or  ten  minutes,  rigidity  disappeared, 
and,  a  few  minutes  afterwards,  movements  took  place  when 
I  excited  the  muscles  or  the  muscular  nerves. 

2d.  I  have  obtained  a  like  result  from  an  experiment  more 
easily  made  than  the  preceding,  and  which  I  have  performed 
more  frequently.  I  divided  transversely  the  body  of  a  living 
guinea-pig,  or  rabbit,  into  two  halves,  on  a  level  with  the  lower 
border  of  the  kidneys,  leaving  no  communication  between  the 
two  halves,  except  by  the  aorta  and  the  vena  cava.  I  then  tied 
the  aorta  immediately  below  the  origin  of  the  renal  arteries. 
The  muscular  irritability  gradually  diminished,  and  in  a  very 
variable  length  of  timef  it  gave  way  to  cadaveric  rigidity.  I 
waited  until  rigidity  had  been  fully  developed  in  all  the  muscles, 
and  then  the  ligature  was  relaxed  and  the  circulation  re-es- 
tablished. Rigidity  disappeared  slowly,  and  the  muscles  and 
the  motor  nerves  resumed  their  vital  properties. 

3d.  In  order  to  ascertain  if  voluntary  movements  and  sensi- 
bility could  be  restored  to  limbs  that  had  been  in  a  state  of  ca- 

*  Treatise  on  Asphyxia.     London,  1834 

t Sometimes  30,  20,  or  even  only  10  minutes  in  weak  animals,  and  from 
1  to  8  or  9  hours  in  strong  animals. 


daveric  rigidity,  I  tied  the  aorta  immediately  behind  the  origin 
of  the  renal  arteries,  in  several  rabbits.  Shortly  afterwards, 
sensibility  and  the  voluntary  movements  disappeared  in  the 
posterior  limbs.  I  waited  until  muscular  irritability  had  given 
way  to  what  is  called  cadaveric  rigidity ;  and  when  that  peculiar 
rigidity  had  existed  for  at  least  twenty  minutes,  I  relaxed  the 
ligature.  Then  circulation  took  place,  and,  in  consequence  of  it, 
sensibility  and  voluntary  movements  re-appeared. 

From  this  experiment  it  results,  that  not  only  local  life,  but  all 
the  properties  and  actions  of  full  life,  can  be  restored  in  limbs 
that  have  been  in  the  state  called  rigor  mortis,  cadaveric  or 
post-mortem  rigidity. 

4th.  On  a  man,  20  years  old,  who  was  guillotined  on  the 
18th  of  June,  1851,  in  Paris,  I  made  an  experiment  similar 
to  some  of  the  preceding.  The  decapitation  took  place  at 
8  o'clock  A.  M.  Ten  hours  afterwards,  i.  e.  ten  minutes  after 
6  o'clock  P.  M.,  the  muscles  of  the  hand,  upon  which  I  intended 
to  experiment,  exhibited  some  slight  manifestations  of  irritability. 
At  7  and  at  7*  o'clock  P.  M.  I  ascertained  that  they  had  lost 
their  irritability.  Shortly  after  they  were  in  a  state  of  cadaveric 
rigidity. 

I  began  the  injection  of  blood  10  minutes  after  9  o'clock  P.  M. 

As  I  wished  to  inject  fresh  human  blood,  and  as  I  could  not 
obtain  any  from  the  hospitals  at  such  an  hour,  I  was  obliged  to 
make  use  of  my  own.  My  friends,  Drs.  F.  Bonnefin  and  Des- 
lauriers,  drew  from  one  of  the  veins  of  my  left  arm  half  a  pound 
of  blood,  which  was  immediately  beaten  and  completely  defibri- 
nated  and  filtered  through  a  cloth. 

As,  in  opposition  to  the  general  opinion,  I  had  found  that  it  is 
not  necessary,  in  transfusion,  to  make  use  of  blood  at  a  tempera- 
ture not  far  from  that  of  warm-blood  animals,  I  left  the  blood 
employed  in  this  experiment  freely  exposed  to  the  atmosphere 
during  all  the  time  of  the  operation.  The  temperature  of  the 
air  was  19°  centigr.  (66°-2  Fahr.j  I  regret  not  having  taker* 
the  temperature  of  the  blood  when  I  began  to  inject  it,  but  rt 
was  probably  about  the  same  as  that  of  the  atmosphere. 

The  injection  was  made  into  the  radial  artery,  a  little  above- 
the  wrist.  The  whole  quantity  of  the  blood  was  injected  in  about 
8  or  10  minutes.  The  arm  operated  on  had  been  separated  from 

8 


90 

the  body,  and  the  blood  injected  came  out  from  all  the  divided 
arteries  and  veins. 

Having  saved  nearly  all  the  blood  which  flowed  from  these 
vessels,  I  injected  it  anew.  The  last  injection  was  made  45 
minutes  after  9  o'clock  P.  M.  Ten  minutes  afterwards  I  found 
that  cadaveric  rigidity  had  ceased  in  the  hand,  and  that  two 
muscles  only,  out  of  the  nineteen  existing  in  that  part,  had  not 
resumed  their  irritability.  Three  muscles  had  become  so  very 
irritable  that  a  slight  mechanical  excitation  was  followed  by  a 
contraction  in  the  whole  length  of  their  fibres. 

At  half  past  one  o'clock  A.  M., — seventeen  hours  and  a  half 
after  decapitation  and  four  hours  after  the  injection  of  blood, — 
there  was  still  a  slight  irritability  in  the  muscles  of  the  hand. 

In  this  experiment  I  found  that  half  a  pound  of  defibri- 
nated  human  blood  was  sufficient  to  give  irritability,  for  seve- 
ral hours,  to  seventeen  of  the  muscles  of  a  hand.* 

5th.  An  experiment  on  another  guillotined  man  gave  me 
more  interesting  results.  The  decapitation  had  taken  place 
at  8  o'clock  A.  M.  on  the  12th  of  July,  1851.  At  5£  o'clock 
P.  M.,  cadaveric  rigidity  existed  in  almost  all  the  muscles  of 
the  arms  and  fore-arms.  I  separated  them  from  the  body,  and 
at  G|  o'clock  I  ascertained  that  cadaveric  rigidity  was  increased, 
and  that  only  a  few  muscles  were  still  slightly  irritable.  At  8 
o'clock  P.  M,  (12  hours  after  the  decapitation)  the  muscles  of  the 
two  arms  were  completely  deprived  of  irritability,  and  in  full  rigi- 
dity, and  the  muscles  of  the  forearms  contracted  only  locally  under 
the  influence  of  a  mechanical  irritation,  and  not  at  all  when  ex- 
cited by  a  powerful  magneto-electric  current.  Two  other  exami- 
nations made,  one  at  9j  and  the  other  at  10  o'clock,  gave  the 
same  results. 

At  10 J  o'clock  two  or  three  bundles  of  fibres  of  one  of  the 
muscles  of  the  fore-arm  were  the  only  parts  where  a  mechanical 
excitation  produced  a  slight  local  contraction.  All  the  other 
muscles  were  perfectly  stiff  and  deprived  of  irritability. 

Twenty-five  minutes  after  10  o'clock  there  was  no  appearance 
of  irritability  remaining  in  any  muscle. 

I  then  began  the  preparations  for  the  injection  of  blood,  with 

*  For  a  full  account  of  the  circumstances  of  this  experiment,  see  my  paper 
>in  the  Gaz.  Medic.de  Paris,  i.  vi.— 1851,  p.  421. 


91 

the  assistance  of  Drs.  Martin-Magron,  F.  Bonnefin,  Crouzet,  and 
Mr.  Moyse. 

We  drew  about  a  pound  of  blood  from  the  carotid  of  a  strong 
dog.  The  blood  was  beaten  and  defibrinated  before  coagulation 
could  take  place  in  it,  and  10  minutes  after  11  o'clock  the  injec- 
tion was  begun.  It  was  made  in  the  brachial  artery  of  the  left 
arm,  in  the  middle  of  its  length,  where  the  arm  had  been  ampu- 
tated. As  soon  as  the  blood  had  been  thrown  in  the  artery, 
some  reddish  spots  appeared  in  different  parts  of  the  skin  of  the 
fore-arm,  of  the  hand,  and  more  particularly  of  the  wrist.  These 
spots  became  larger  and  larger,  and  the  skin  had  the  appearance 
it  has  in  rubeola.  Soon  after,  the  whole  surface  of  the  skin  was 
of  a  violet  reddish  hue.  In  a  few  minutes  this  color  disappeared, 
and  was  replaced  by  the  natural  hue  of  the  skin  during  life.  The 
skin  became  elastic  and  soft,  as  in  a  living  man,  and  we  saw  the 
bulbs  of  its  hair  becoming  erected  and  presenting  the  appearance 
called  eutis  anserina.  By  increasing  and  diminishing  alternately 
the  impulsion  given  to  the  blood,  we  succeeded  in  producing  the 
beatings  of  the  pulse  in  the  radial  artery.  The  veins  were  dis- 
tinct and  full  as  during  life. 

A  short  time  after,  the  fingers,  which  had  been  extremely  stiff, 
relaxed,  and  rigidity  disappeared  also  in  the  other  parts  of  the 
limb. 

Forty-five  minutes  after  11  o'clock  P.  M.,  irritability  had  re- 
turned in  all  the  muscles  of  the  limb  operated  on.  The  degree 
of  irritability,  more  particularly  in  the  muscles  of  the  arm,  (tri- 
ceps, biceps  and  others)  was  very  considerable,  and  much  greater 
than  I  had  seen  it  at  the  time  the  corpse  was  first  examined 
(about  five  o'clock  P.  M.)  Irritability  was  still  present  in  almost 
all  the  muscles  of  this  limb  at  4  o'clock  A.  M.,  (20  hours  after 
the  decapitation,)  when  I  was  obliged,  from  extreme  fatigue,  to 
abandon  further  investigation. 

The  blood  injected  was  at  23°  centig.  (73°.4  Fahr.)  when  I 
began  the  operation,  and  the  atmosphere  was  at  19j°  centig. 
(66.66  Fahr.) 

In  this  experiment,  about  one  pound  of  defibrinated  dog's 
blood  gave  irritability  for  more  than  five  hours  to  all  the 
muscles  of  a  limb,  from  the  middle  of  the  arm  to  the  hand. 

6th.  Every  one  knows  the  singular  fact,  that  Vibriones  and 


92 

other  Infusoria,  when  desiccated,  will  live  when  they  are  put  into 
water.  It  is  also  perfectly  known  that  seeds,  after  many  centu- 
ries, may  grow  when  put  in  the  earth.  I  have  found  something 
of  the  same  kind  in  higher  organisms ;  it  is  that  muscles,  in  a 
certain  condition,  after  having  been  separated  from  the  body 
for  many  days,  may  recover  their  irritability. 

Dr.  Coze,  of  Strasbourg,  has  found  that  chloroform  injected 
into  the  main  artery  of  a  limb  produces  instantly  the  strongest 
rigidity,  and  that  if  blood  is  allowed  to  circulate  again  in  the 
limb,  life  appears  again  in  it.  I  have  gone  farther,  and  found 
that  if  a  limb,  in  which  an  injection  of  chloroform  has  been  made, 
is  separated  from  the  body,  it  is  able,  under  the  influence  of  an 
injection  of  blood,  to  recover  its  muscular  irritability  2,  3,  4,  5 
and  (in  one  case)  10  days  after  the  rigidity  was  produced. 
1  think  Mr.  Edouard  Robin  is  right  in  admitting  that  chloroform 
prevents  the  chemical  changes  that  take  place  in  organic  bodies 
after  death,  and,  if  it  is  so,  we  can  understand  why  an  injection 
of  blood  made  so  long  after  the  limb  has  been  separated  from  the 
body,  may  reproduce  irritability.  One  day  is  not  more  than  one 
hour,  if,  during  it,  there  is  no  alteration  produced  in  the  muscles. 

It  appears,  nevertheless,  that  chloroform  does  not  entirely 
prevent  the  alterations  of  muscles,  because,  in  my  experiments,  I 
have  found  that  the  longer  the  limbs  had  been  separated  from 
the  body,  the  greater  was  the  quantity  of  blood  necessary  to  re- 
produce irritability. 

7th.  I  lately  made  an  experiment,  with  the  view  of  ascertain- 
ing how  long  a  limb,  separated  from  the  body  of  an  animal,  may 
be  kept  alive  by  means  of  injected  blood.  I  succeeded  in 
retaining  local  life  in  one  of  the  limbs  of  a  rabbit  more  than 
41  hours.  The  animal  was  a  very  vigorous,  full  grown  one.  I 
killed  it  by  hemorrhage,  and,  two  hours  afterwards,  rigidity  had 
begun  in  most  of  the  muscles  of  the  two  posterior  limbs,  and  only 
a  few  bundles  of  muscular  fibres  had  still  a  slight  irritability.  A 
first  injection  of  defibrinated  blood  was  then  pushed  in  the  femo- 
ral artery  of  the  right  posterior  limb.  Fifteen  minutes  after  the 
beginning  of  the  injection,  local  life  fi.  e.  irritability)  was  re- 
stored in  the  limb  receiving  blood,  and  cadaveric  rigidity  had 
disappeared. 

The  manner  of  testing  this  irritability  was  the  same  as  that  of 


93 

Glisson,  Gorter,  and  all  the  experimenters  of  the  two  last  centu- 
ries,— I  mean  by  mechanical  excitation.  I  did  not  use  galvanism, 
as  it  exhausts  muscular  irritability  too  much,  as  Autenrieth, 
Pfaff  and  many  other  observers  have  shown  long  ago.  Being 
aware  of  this  fact,  I  have  always,  in  my  preceding  experiments, 
made  use  of  galvanism  for  a  very  short  time  only. 

Three  hours  after  the  death  of  the  rabbit,  irritability  still 
existed  in  the  right  limb  (the  injected  one,)  while  the  left  was 
perfectly  rigid  and  had  not  the  slightest  irritability.  Half  an 
hour  later,  rigidity  had  begun  again  in  the  right  limb ;  blood 
was  injected  anew,  rigidity  disappeared,  and  local  life  returned. 
From  this  moment  until  11  o'clock,  P.  M.,  (death  liad  occurred 
at  6  o'clock,  A.  M.  of  the  same  day,)  blood  was  injected  many 
times.  Rigidity  did  not  return,  and  the  vital  property  of  the 
muscles  was  maintained.  Of  course  the  left  limb,  during  that 
time,  remained  rigid,  and  had  not  the  slightest  irritability. 

From  11  o'clock,  P.  M.  until  6  o'clock,  A.  M.  the  succeeding 
day,  an  abundant  injection  of  blood  was  made  every  twenty  or 
twenty-five  minutes.  The  irritability  was  not  powerful,  but  it 
existed  in  all  the  muscles  of  the  limb.  There  was  no  rigidity 
at  all. 

The  injections  were  then  made  more  frequently — once  in  each 
quarter  of  an  hour — until  three  o'clock,  P.  M.,  at  which  time  I 
was  obliged  to  stop  them  for  an  hour  and  a  half. 

At  half  past  four  I  found  the  limb  rigid,  and  only  a  few 
bundles  of  muscular  fibres  still  irritable.  A  very  abundant 
injection  was  then  practised,  and  rigidity  soon  disappeared, 
giving  way  to  irritability.  From  this  time  to  11  P.  M.,  a  great 
many  injections  were  made,  and  irritability  was  maintained.  I 
was  then  obliged  to  give  up  the  experiment.  At  that  moment 
irritability  was  strong  in  all  the  muscles  of  the  injected  limb, 
except  some  parts  of  their  pelvic  extremities  that  had  not 
received  a  sufficient  quantity  of  blood. 

The  next  morning  that  limb  was  in  full  and  energetic  rigidity. 
The  other  limb  had  already  lost  its  rigidity,  and  had  an  evident 
smell  of  putrefaction.  The  third  day  after  the  death  of  the 
animal,  rigidity  was  strong  in  the  injected  limb,  while  the  other 
was  in  an  advanced  state  of  putrefaction. 

If  we  compare  these  two  limbs,  we  find,  1,  That  the  injected 


94 

one  had  a  strong  irritability  at  the  end  of  forty-one  hours  after 
the  death  of  the  animal ;  2,  That  its  rigidity  gave  way  to  putre- 
faction only  at  the  eightieth  hour ;  3,  That  it  was  in  complete 
putrefaction  only  at  the  ninety-fourth  hour.  The  other  limb 
was  in  full  rigidity  at  the  fifth  hour  after  the  death  of  the 
animal ;  its  rigidity  gave  way  to  putrefaction  at  the  forty- 
eighth  hour ;  and  it  was  in  complete  putrefaction  at  the  seven- 
tieth hour. 

From  all  the  experiments  above  related,  it  appears  that  life 
may  be  reproduced  or  maintained  in  muscles  and  nerves  by 
mere  injections  of  blood.  I  have  found,  also,  that  life  may  be 
reproduced  by  the  same  means  in  the  spinal  cord  and  in  the 
brain.  I  will  publish  these  facts  in  another  article. 

It  is  nearly  indifferent  in  these  experiments  whether  we  use 
venous  or  arterial  blood  ;  but  it  is  absolutely  necessary  to  employ 
red  blood,  i.  e.  oxygenated  blood. 

I  have  tried,  sometimes,  arterial  blood,  rendered  black  by 
the  substitution  of  nitrogen  or  hydrogen  for  a  great  part  of  its 
oxygen,  and  I  have  found  that  such  blood  was  unable  to  repro- 
duce the  vital  properties  of  nerves  and  muscles. 

Oxygen  is  necessary,  either  because  it  prevents  the  blood-glo- 
bules from  being  altered,  or  because  it  acts  directly  on  muscles,  as 
Gustavus  Liebig  has  found  it  does  on  their  external  surface, 
when  exposed  to  air.  I  believe  it  is  necessary  for  both  these  rea- 
sons. 

I  cannot  say  how  long  after  the  beginning  of  cadaveric 
rigidity  in  a  muscle,  oxygenated  blood  can  reproduce  local  life. 
In  the  second  of  the  two  decapitated  men,  on  whom  I  ex- 
perimented, rigidity  had  existed  at  least  five  hours  before  the 
injection  was  begun.  I  believe  that  the  stronger  the  animal  is, 
the  more  easy  it  is  to  reproduce  local  life  in  rigid  limbs,  by 
injection  of  blood.  In  limbs  of  weak  rabbits,  I  have  found  it 
impossible,  two  hours  after  the  beginning  of  cadaveric  rigidity, 
to  reproduce  local  life.  In  a  very  strong  dog  I  have  reproduced 
muscular  irritability  four  hours  after  rigidity  had  been  fully 
developed. 

Ten,  twelve,  or  fourteen  hours  after  rigidity  had  taken  place, 
in  human  limbs,  I  have  tried  in  vain  to  re-establish  local  life. 

I  have  ascertained  that  pure  serum  of  blood,  or  milk,  or  albu- 


95 

men  of  eggs,  are  unable  to  produce  any  apparent  change  in 
rigid  limbs. 

The  following  conclusions  are  to  be  drawn  from  the  facts 
related  in  this  article  : 

1st.  Red  blood,  i.  e.  richly  oxygenated  blood  (arterial  or 
venous)  is  able  to  revive  irritability  in  muscles,  four  or  five  hours 
after  these  organs  have  lost  this  property. 

2d.  Red  blood  is  able  to  revive  the  vital  properties  of 
nerves  and  nervous  centres,  when  these  properties  have  not  been 
lost  for  more  than  about  an  hour. 

3d.  Muscular  irritability  can  be  maintained  for  more  than  41 
hours,  by  mere  injections  of  blood,  in  limbs  separated  from  the 
body  of  a  rabbit. 

4th.  Muscular  irritability  may  be  re-established  in  limbs  ren- 
dered rigid  by  chloroform  for  many  days,  even  ten  days. 

XXIX CASES  OF  LOSS  OF  SENSIBILITY  ON  ONE  SIDE  OF  THE  BODY. 

AND  LOSS  OF  VOLUNTARY  MOVEMENTS  ON  THE  OTHER  SIDE. 

It  has  been  objected  to  me  that  if  the  transmission  of  sensitive 
impressions,  in  the  spinal  cord,  takes  place,  as  I  have  tried  to 
prove  in  a  former  part  of  this  sketch  (Art.  XIX,)  so  that  those 
coming  from  the  left  side  of  the  body,  are  mostly  conveyed  to 
the  sensorium  along  the  right  side  of  the  spinal  cord, — et  vice 
versa — physicians  should  have  some  times  found  in  man  the 
same  thing  that  I  have  discovered  in  animals. 

Many  reasons  have  prevented  physicians  from  making  such  a 
discovery:  In  the  first  place,  an  injury  or  a  pathological  altera- 
tion, limited  to  a  lateral  half  of  the  spinal  cord,  is  very  rare. 
Besides,  the  idea  that  there  is  no  crossing  of  fibres  in  the  spinal 
cord,  has  been  an  obstacle  to  a  thorough  examination  of  many 
pathological  cases,  and  it  has  been  so  in  a  case  observed  by  Boyer. 

There  are  but  few  cases  on  record  in  which  there  was  a  loss 
or  a  diminution  of  sensibility  on  one  side,  and  of  voluntary 
movements  on  the  other.  I  will  give  here  a  short  account  of 
some  cases  of  that  kind,  which  are  very  interesting. 

The  first  one  I  will  relate  has  been  observed  by  Boyer: 

A  drummer,  of  the  National  Guard  of  Paris,  received  a  wound 
in  the  back  of  his  neck.  A  sword  had  been  thrown  at  him,  and 
had  penetrated  the  superior  part  of  the  right  lateral  half  of  the 


96 

neck.  An  incomplete  paralysis  of  movement  took  place  in  the 
right  side  of  the  body,  and,  some  time  after,  it  was  accidentally 
discovered  that  sensibility  was  lost  in  many  parts  of  the  left 
side  of  the  body.  After  twenty  days  the  wound  was  cured,  and 
the  man  went  out  of  the  hospital,  still  paralysed. 

From  what  we  know  of  that  case,  it  appears  that  the  sword  had 
incompletely  divided  the  right  lateral  half  of  the  spinal  cord. 
The  paralysis  of  motion  on  the  right  side  of  the  body  was 
certainly  produced  by  the  division  of  a  part  of  the  anterior 
column,  and,  as  the  instrument  had  penetrated  the  right  side  of 
the  back  of  the  neck,  it  must  have  divided  the  parts  between  the 
anterior  column  of  the  spinal  marrow  and  the  external  surface  of 
the  right  side  of  the  neck.  These  parts,  besides  the  muscles  and 
bones,  are  the  lateral  and  posterior  columns  and  the  gray  matter 
of  the  right  half  of  the  spinal  cord.  So  that  in  this  case  nearly 
the  same  injury  and  also  the  same  morbid  phenomena  had  ex- 
isted as  in  the  animals  on  which  I  have  divided  a  lateral  half  of 
the  spinal  cord. 

The  following  case  is  still  more  interesting.  It  has  been  re- 
corded  by  Dr.  R.  Dundas,  Surgeon  of  the  Hospital  of  Bahia. 

A  mason  fell  on  his  back  from  an  height  of  20  feet.  After 
having  recovered  his  consciousness,  he  discovered  that  all  the 
left  side  of  his  body,  from  the  shoulder  to  the  foot,  was  paralyzed 
as  to  motion,  without  the  slightest  alteration  of  sensibility,  and 
that  the  right  side  in  which  the  movements  were  free,  was  com- 
pletely deprived  of  sensibility. 

Three  important  facts,  precisely  like  those  I  have  discovered 
in  animals  after  the  transversal  section  of  a  lateral  half  of  the 
spinal  cord,  existed  in  this  case  : 

1st.  A  morbid  exaltation  of  sensibility  in  the  side  where  move- 
ment was  lost. 

2d.  A  diminution  of  temperature  in  the  side  where  the  para- 
lysis  of  sensibility  existed. 

3d.  An  increase  in  temperature  in  the  side  where  the  paralysis 
of  movement  existed.* 

*  In  a  former  part  of  this  sketch  (Art.  xxii.)  I  have  related  facts  proving 
that  animal  heat  may  be  increased  after  injuries  to  the  spinal  cord.  I  have 
learned  since,  that  Prof.  D.  Gilbert  has  observed  a  case  of  fracture  of  the 
spine,  in  which  the  temperature  of  the  paralyzed  parts  was  increased.  Prof. 
Dunglison  has  also  stated  that  the  paralyzed  side  in  hemiplegic  patients 
may  have  an  elevation  of  temperature. 


97 

When  Dr.  Dimdas  published  this  curious  case,  the  patient  was 
living  and  improving  ;  so  we  do  not  know  what  was  the  altera- 
tion existing  in  the  spinal  cord. 

H.  Ley,  in  a  letter  to  Sir  Charles  Bell,  relates  the  following 
case :f 

Mrs.  W.,  after  a  profuse  hemorrhage,  became  paralytic.  Upon 
one  side  of  the  body  there  was  a  loss  of  sensibility,  without,  how- 
ever, any  corresponding  diminution  of  power  in  the  muscles  of 
volition.  The  breast,  too,  upon  that  side,  partook  of  the  insen- 
sibility, although  -the  secretion  of  milk  was  as  copious  as  in  the 
other.  She  could  see  the  child  sucking  and  swallowing,  but  she 
had  no  consciousness,  from  feeling,  that  the  child  was  so  occu- 
pied. 

Upon  the  opposite  side  of  the  body  there  was  defective  power 
of  motion,  without,  however,  any  diminution  of  sensibility.  The 
arm  was  incapable  of  supporting  the  child  ;  the  hand  was  power- 
less in  its  grasp  ;  and  the  leg  was  moved  with  difficulty,  and  with 
the  ordinary  rotatory  movement  of  a  paralytic  patient ;  but  the 
power  of  sensation  was  so  far  from  being  impaired  that  she  con- 
stantly complained  of  an  uncomfortable  sense  of  heat,  a  painful 
tingling,  and  more  than  the  usual  degree  of  uneasiness  from 
pressure,  or  other  modes  of  slight  mechanical  violence. 

She  again  proved  pregnant.  Her  delivery  was  easy  :  but  after 
about  ten  days  she  complained  of  numbness  on  both  sides. 
Her  articulation  was  indistinct ;  she  became  more  and  more  in- 
sensible, and  sank,  completely  comatose. 

No  positive  disorganization  of  the  brain  could  be  detected. 
The  ventricles,  however,  contained  more  than  usual  serum  ;  and 
there  were  found  thickening  and  increased  vascularity  of  the 
membranes,  with  moderately  firm  adhesion  in  some  parts ;  in 
others,  an  apparently  gelatinous,  transparent  and  colorless  de- 
posit interposed  between  them. 

Unfortunately,  no  examination  of  the  spinal  cord  was  made. 

In  this  case  there  was  very  likely,  as  in  my  experiments,  an 
increase  in  the  temperature  of  the  side  paralyzed  of  motion.  The 
writer  merely  says  that  the  patient  was  constantly  complaining 
of  an  uncomfortable  sense  of  heat.  There  was,  as  in  my  animals, 
an  evident  increase  in  sensibility  on  that  side. 

fThe  nervous  system  of  the  human  body.  By  Ch.  Bell.  3d  ed.  London, 
1844,  p.  245. 


98 

M.  Monod*  has  related  the  case  of  a  man  who,  after  having 
felt  a  sudden  pain  in  his  back,  became  paralyzed  in  the  motion 
of  the  right  inferior  limb.  Sensibility  was  entire  on  this  side, 
but  on  the  left  side,  where  the  movements  were  entire,  sensibility 
was  entirely  lost  from  the  breast  to  the  foot.  There  was  at  first 
no  fever.  The  patient  died  34  days  after  the  beginning  of  this 
affection. 

The  brain  and  its  membranes  were  normal.  A  hemorrhage 
had  taken  place,  and  blood  was  found  in  the  right  side  of  the 
central  gray  matter,  in  the  neighborhood  of  the  anterior  column 
in  the  dorsal  and  lumbar  regions. 

This  case  is  assuredly  a  very  remarkable  one,  and  in  accord- 
ance with  my  experiments. 

The  conclusion  to  be  drawn  from  these  four  cases  is,  that  in 
man  as  well  as  in  animals,  there  appears  to  be  a  crossing  of  the 
sensitive  nerve-fibres  in  the  spinal  cord. 

XXX. — ON    THE    DIFFERENT   DEGREES    OF   EXCITABILITY   OF    THE 
DIFFERENT   PARTS   OF   THE   SENSITIVE   NERVE-FIBRES. 

It  is  a  well-known  fact,  that  an  excitation  of  the  skin  or  of  a 
mucous  membrane,  produces  a  greater  pain  or  a  greater  reflex 
action  than  that  of  the  nerve  trunk,  from  which  these  parts  re- 
ceive their  nerve-fibres.  For  instance,  a  slight  excitation  of  the 
laryngeal  mucous  membrane  produces  coughing,  while  an  excita- 
tion of  the  vagus  nerve  very  rarely  produces  the  same  effect. 
Therefore,  there  is  a  notable  difference  between  the  peripheric 
extremity  of  a  nerve-tube  and  its  part  contained  in  a  nerve- 
trunk. 

The  existence  of  a  peculiar  organ  in  the  skin  (the  corpuscles 
of  touch  of  Wagner)  has  not  much  (if  it  has  anything)  to  do  with 
the  different  degrees  of  excitability  of  nerve-tubes  in  the  skin 
and  in  the  trunks  of  nerves.  The  corpuscles  of  touch  do  not 
exist  in  the  mucous  membranes,  and  if  they  exist  in  the  skin  of 
frogs,  turtles,  etc.,  it  is  in  a  very  small  number  ;  and,  neverthe- 
less, the  degree  of  excitability  of  nerve-fibres  in  these  parts  is 
much  superior  to  that  of  the  fibres  of  the  nerve-trunks. 

Some  very  striking  differences  exist  in  the  degree  of  excita- 

*  Bulletin  de  la  Societe  Anatornique,  No.  xviii.  p.  349. 


99 

bility  of  centripetal  nerve-fibres  in  the  five  following  different 
parts  of  their  length. 

1st.  The  part  contained  in  the  skin. 

2d.  The  part  of  a  nerve  extending  from  the  skin  to  the  spinal 
cord. 

3d.  The  posterior  roots  of  the  spinal  nerves. 

4th.  The  part  of  the  posterior  roots  attached  to  the  spinal 
cord. 

5th.  The  part  of  the  cutaneous  nerve-fibres  contained  in  the 
gray  matter  of  the  spinal  cord. 

The  fibres  existing  in  the  gray  matter  of  the  spinal  cord  ap- 
pear to  be  inexcitable,  at  least  by  our  ordinary  means  of  excita- 
tion. Of  the  four  other  parts,  the  less  excitable  is  the  nerve  be- 
tween the  ganglion  and  the  skin.  The  excitability  of  the  pos- 
terior roots  is  less  than  that  of  the  skin  and  that  of  their  part 
attached  to  the  spinal  cord.  Of  these  two  last  parts  the  skin  is 
less  excitable  than  the  other. 

I  measured  the  excitability  by  the  degree  of  pain  or  of  reflex 
action.  The  differences  are  much  more  easily  found  for  the  re- 
flex action  than  for  the  pain. 

Is  it  because  they  have  been  connected  with  the  cells  of  the 
central  gray  matter  of  the  spinal  cord,  that  the  centripetal  fibres, 
contained  in  that  gray  matter,  are  not  excitable  ?  If  it  is  so, 
there  is  a  difference  between  these  cells  and  those  of  the  gan- 
glions on  the  posterior  roots,  because  the  connection  of  these  fibres 
with  the  cells  of  these  ganglions  does  not  prevent  their  being 
excitable.* 

From  the  facts  above  related  I  conclude  that  the  same  nerve- 
fibre,  in  different  parts  of  its  length,  may  have  very  different  de- 
grees of  excitability. 

XXXI. — THE  AUDITIVE   NERVE   IS   A   NERVOUS    CENTRE. 

In  an  anatomical  point  of  view  there  is  no  doubt  that  the 
auditive  nerve  is  a  nervous  centre.  This  is  proved  by  the  fact 
that  cells  of  gray  matter  are  found,  not  only  in  the  terminal  part 
of  the  nerve,  but  also  in  its  trunk,  in  many  animals,  according 
to  the  researches  of  Stannius,  Corti,  Kb'lliker,  and  myself. 

In  a  physiological  point  of  view,  the  fact  I  have  discovered, 
(see  Art.  V.  p.  21,)  viz.,  that  any  injury  to  the  acoustic  nerve 


100 

produces  turning,  is  sufficient  to  prove  that  it  is  a  nervous  centre. 

The  degree  of  pain  produced  by  an  excitation  of  this  nervous 
centre  appears  to  be  as  considerable  as  that  caused  by  a  similar 
excitation  of  the  trigeminal  nerve.  I  will  publish  soon  an  ac- 
count of  the  strange  effects  produced  in  different  parts  of  the  body 
in  consequence  of  an  injury  of  that  nervous  centre.  I  will  merely 
say  here  that,  after  such  an  injury,  there  are  muscles  which 
appear  to  be  slightly  paralyzed.  Besides,  there  seems  to  be  a 
notable  hyperaesthesia  of  the  skin  everywhere. 

Flourens  has  found  that  a  section  of  the  semi-circular  canals 
in  birds  and  some  mammals  produces  a  peculiar  disorder  in  the 
movements  of  the  head,  and,  in  some  .cases,  turning.  He  says 
that  the  auditive  nerve  must  be  considered  as  composed  of  two 
nerves:  one  going  to  the  semi- circular  canals  and  possessing  a 
peculiar  power  on  the  movements  of  the  body,  and  the  other, 
the  vestibular  or  true  auditory  nerve.  What  I  have  found  on 
frogs  is  in  opposition  to  these  views.  A  section  of  the  semi- 
circular canals,  in  these  amphibia,  does  not  produce  any  effect 
on  the  movements  of  the  body,  and  the  slightest  excitation  of 
the  true  auditive  nerve  is  sufficient  to  produce  pain,  hyperaesthe- 
sia,  turning,  and  other  strange  effects  on  many  muscles  of  the 
body. 

I  have  sometimes  seen  turning  produced  after  the  mere  laying 
bare  of  the  kind  of  bladder,  containing  the  terminal  part  of  the 
auditive  nerve,  in  frogs.  So  slight  may  be  the  excitations  on 
that  nerve  sufficient  to  produce  turning,  that  very  likely  turning 
after  the  laying  bare  of  that  bladder  was  the  result  of  some 
slight  mechanical  injury  of  the  nerve.  The  rapidity  of  turning 
and  the  smallness  of  the  circle  then  described  are  in  proportion 
to  the  degree  of  injury  to  the  nerve.  When  the  two  auditive 
nerves  are  injured,  the  animal  turns  on  the  side  most  injured. 
Sometimes,  instead  of  turning,  the  animals  roll  around  the  longi- 
tudinal axis  of  their  body;  this  takes  place  in  very  strong 
animals  after  the  terminal  part  of  the  nerve  has  been  entirely 
crushed. 

In  frogs  deprived  of  their  cerebral  lobes,  the  same  effects  are 
produced  after  injuries  of  the  auditive  nerve,  as  in  unmutilated 
frogs. 


101 


XXXII. — ON  APPARENTLY  SPONTANEOUS  ACTIONS  OF  THE  CONTRAC- 
TILE TISSUES   OF  THE  ANIMAL   BODY. 

All  the  contractile  tissues  of  the  animal  body  (the  muscles  of 
the  trunk  and  limbs,  the  muscular  layers  of  the  digestive  canal, 
the  iris,  the  uterus,  the  dartos,  the  cellular  tissue,  etc.)  present, 
sometimes,  apparently  spontaneous  contractions.  I  give  this 
name  to  contractions  which  are  not  the  result  of  an  external 
excitation  or  of  an  excitation  produced  by  the  nervous  system  on 
the  contractile  tissues.  These  contractions  may  be  permanent 
or  momentary,  rhythmical  or  irregular,  slight  or  very  powerful. 
One  of  their  causes,  if  not  their  only  cause,  appears  to  be  an 
excitation  directly  produced  on  the  contractile  fibres  by  the 
carbonic  acid  existing  in  the  blood. 

1.  Contractions  in  the  muscles  of  the  face  after  a  section  of  the 
facial  nerve. — My  friend  Dr.  Martin-Magron  and  myself  have 
discovered  that  after  the  section  of  one  of  the  facial  nerves,  on  a 
rabbit,  the  face  becomes  very  quickly  deviated,  not  on  the  healthy 
side,  as  it  is  known  to  be  in  man,  but,  strange  to  say,  on  the 
paralysed  side.  The  deviation,  very  slight  at  first,  increases 
gradually  during  one  or  two  weeks,  and  then  it  is  so  considerable 
that  the  middle  of  the  lips  is  at  a  distance  of  four,  five  or  six 
lines  from  its  natural  situation.  There  is  an  evident  state  of 
contraction  in  all  the  paralysed  muscles.  When  the  animal  is 
excited,  or  when  its  respiration  is  somewhat  disturbed  or  pre- 
vented, the  paralytic  muscles  tremble,  and  sometimes  they  have 
rhythmical  contractions  and  relaxations. 

The  contractions  of  these  muscles  may  be  so  considerable  that 
the  bones  themselves,  and,  secondarily,  the  teeth,  may  be  de- 
formed. In  one  case,  on  a  rabbit  which  I  had  kept  living  twenty- 
one  months  after  the  extirpation  of  one  of  the  facial  nerves,  not 
only  the  superior  and  inferior  jaws  were  by  far  less  developed  on 
the  paralysed  side  than  on  the  other,  but  the  anterior  part  of 
the  superior  maxillary  bone  was  deviated  towards  the  paralysed 
side,  so  that  the  middle  line  of  the  roof  of  the  mouth  was  curved 
and  presented  a  great  concavity  on  the  paralysed  side  and  a  cor- 
responding convexity  on  the  other. 

When  the  two  facial  nerves  have  been  divided,  there  is  no 


102 

deviation,  but  there  is  an  evident  state  of  contraction  in  all  the 
paralysed  muscles,  particularly  around  the  lips.* 

When  one  of  the  facial  nerves  is  divided  on  a  dog,  on 
a  cat,  or  on  a  guinea  pig,  there  is  generally  no  deviation 
on  either  side.  But  very  frequently  there  are  convulsive  move- 
ments, and  sometimes  rhythmical  contractions,  in  the  para- 
lyzed side  of  the  face.  One  of  these  two  kinds  of  movements 
always  exists  in  young  cats.  They  are  increased,  or  produced 
when  they  do  not  exist,  in  dogs  and  guinea-pigs,  almost  every 
time  we  prevent  the  animal  from  breathing  freely.  Once,  on  a 
very  vigorous  guinea  pig,  upon  which  one  of  the  facial  nerves 
had  been  torn  away,  I  saw  alternate  contractions  and  relaxa- 
tions taking  place,  without  a  relapse,  for  eight  or  ten  days  after 
the  operation  in  the  paralysed  muscles.  After  that  time,  these 
tremblings  appeared  only  when  the  circulation  and  the  respira- 
tion were  rendered  very  active,  or  when  the  respiration  was  pre- 
vented or  diminished.  In  the  case  of  an  impaired  respiration, 
the  strength  and  frequency  of  these  movements  were  in  propor- 
tion to  the  degree  of  asphyxia.  During  many  months,  the  same 
phenomena  existed  in  this  animal. 

I  ought  to  say  that  in  all  the  experiments  above  related,  the 
nerve  could  not  have  any  share  in  the  movements,  because, 
the  fifth  day  after  the  division,  or  after  the  extirpation  of  a 
portion  of  it,  the  peripheric  part  had  entirely  lost  its  vital 
property. 

In  man,  as  Dug£s  justly  remarks,  as  long  as  there  is  no 
attempt  at  movement,  voluntary  or  emotional,  the  face  remains 
without  any  deviation,  in  cases  of  facial  hemiplegia,  which  have 
not  lasted  a  long  time. 

2.  On  spontaneous  rhythmical  or  irregular  contractions  in 
muscles  of  animal  life,  after  death — It  is  a  very  important  fact 
in  connection  with  the  theory  of  the  action  of  the  heart,  as  I 
will  try  to  prove  hereafter,  that  other  muscles,  and  particularly 
muscles  of  animal  life,  are  capable  of  having  rhythmical  move- 
ments. This  fact  I  have  discovered  in  the  following  cases : 

a.  After  the  division  of  the  nerves  of  the  ischiatic  and  lumbar 

*  Dr.  Martin-Magron  and  myself  have  found  that  death  occurs  from  inani- 
tion in  all  the  species  of  mammals  on  which  we  have  divided  the  two  facial 
nerves.  After  the  operation  they  cannot  swallow :  we  do  not  know  why. 


103 

plexuses,  on  one  side,  in  mammals,  if  we  suddenly  asphyxiate 
the  animal,  we  see,  at  first,  convulsive  movements  in  the  three 
limbs  and  in  other  parts  of  the  body  not  paralysed.  After  one, 
two  or  three  minutes,  these  movements  cease,  and  there  are  only 
some  tremblings  in  the  muscles  of  these  parts.  The  paralysed 
limb  has  no  movement  at  all  during  one  or  two  minutes,  after 
which  time,  suddenly,  contractions  in  many  bundles  of  muscular 
fibres  partially  take  place.  In  the  same  bundle  the  contractions 
sometimes  appear  to  come  regularly  one  after  the  other.  In 
some  cases  I  have  seen,  besides  these  tremblings,  movements  of 
the  entire  limb,  consisting  of  some  successive  flexions  and  exten- 
sions of  the  limb,  and  after  these  movements  had  ceased,  con- 
tractions limited  to  various  bundles  of  fibres  appeared.  In  these 
cases  the  action  of  the  muscles  began  very  late  after  death,  and 
once,  only  six  minutes  after  the  beginning  of  asphyxia,  which 
lasted  two  minutes  and  a  half. 

b.  Nearly  the  same  movements  of  which  I  have  spoken   as 
existing  frequently  in  the  face,  during  life,  in  rabbits  and  guinea- 
pigs,  after  the  section  of  the  facial  nerves,  exist  always,  either 
during  agony  or  a  little  after  death.     They  are  generally  pro- 
duced by  partial  contractions  and  relaxations  of  the  different 
bundles  of  fibres  of  the  various  muscles.     It  is  rare  to  see  all 
the  bundles  composing  one  muscle  contracting  together.     These 
phenomena  last  five,  six  or  eight  minutes  after  the  last  respi- 
ration.   There  are  also  such  movements  in  the  face  during  agony 
and  after  death,  when  the  nerves  have  not  been  cut  and  when 
there  is  no  paralysis ;  but  then  the  movements  appear  later  and 
do  not  last  so  long  as  in  paralysed  muscles. 

c.  I  have  seen  in  many  rabbits  apparently  spontaneous  rhyth- 
mical contractions  in  the  respiratory  muscles.      In  about  ten 
rabbits,  out  of  forty  or  fifty,  the  following  phenomena  were 
very  decided ;  on  the  others  they  were  slight,  and  sometimes 
very  slight,   but  in  all  cases   a   part  of  them  always   existed. 
I  open  the  abdominal  cavity  and  expose  the  bowels  to  the  action 
of  a  cold  atmosphere,  so  as  to  lower  the  temperature  of  the 
animal ;  after  some  minutes  I  make  a  little  opening  in  one  side 
of  the  chest,  and,  at  last,  after  a  few  minutes  more,  I  open 
largely  one  side  of  the  chest.    Generally,  in  such  circumstances, 
the  respiratory  movements  continue  to  take  place  with  energy. 


104 

I  then  take  away  the  sternum  and  divide  the  two  diaphragmatic 
nerves.  The  movement  of  the  diaphragm,  nevertheless,  continues, 
and  it  exists  rhythmically  together  with  the  movements  of  the 
other  respiratory  muscles.  Six,  eight  or  ten  minutes  afterwards 
the  movements  of  the  diaphragm  are  still  regular,  (there  are  from 
five  to  twenty  contractions  in  a  minute ;)  the  intercostal  muscles 
present  then  only  partial  contractions.  The  different  bundles  of 
fibres  of  these  muscles  contract  separately  one  after  the  other, 
but  the  same  bundle  has  generally  regular  contractions  and  re- 
laxations. At  that  time  I  destroy  the  spinal  cord,  and  see  that 
the  movements  of  the  diaphragm  and  of  the  intercostal  muscles 
are  not  changed  after  this  operation  ;  they  last  for  nearly  a  quar- 
ter of  an  hour,  and  in  some  cases  much  longer  ;  their  regularity 
subsists.  In  the  diaphragm,  long  after  the  general  movement 
has  stopped,  there  are  regular  or  irregular  contractions  of 
many  bundles  of  fibres  for  one,  two,  three  hours,  and  sometimes 
more. 

3.  Deviation  of  limbs  produced  by  a  contraction  of  paralysed 
muscles. — In  pigeons,  after  the  destruction  of  all  the  lumbar  part 
of  the  spinal  cord,  the  two  posterior  limbs  are  completely  para- 
lysed.    The  muscles  then  are  soft,  and  the  different  parts  of  the 
limbs  do  not  resist  at  all,  when  we  try  to  put  them  in  flexion  or  in 
extension.     But  after  a  few  days  the  paralysed  muscles  become 
harder,  and  after  a  few  weeks  there  is  an  evident  state  of  con- 
traction in  them.     The  limb  is  generally  kept  in  a  state  of  exten- 
sion,  and  deviated  on   one    side  or  the  other.     The  deviation 
becomes  considerable  after  some  months. 

Very  likely  it  is  owing  to  the  same  cause  that  club-foot  and 
other  deviations  are  produced  in  embryos,  after  a  destruction  or 
an  absence  of  development  of  the  spinal  cord. 

4.  Rhythmical  movements  in  the  eye  of  the  Ink-fish.  (Loligo 
sepia,  L.) — The  ciliary  muscle  so  well  described  by  Dr.  W.  Clay 
Wallace,  of  New  York,  in  the  eyes  of  superior  animals,  is  strongly 
developed  in  the  ink-fish.     After  an  eye  of  this  mollusc  has  been 
separated  from  the  body,  I  have  sometimes  found  very  singular 
and  perfectly  rhythmical  movements   produced  by  the  ciliary 
muscle.     These  movements  consisted  in  alternative  contractions 
and  relaxations  of  some  parts  of  that  muscle.    At  every  contrac- 
tion a  notable  depression  was  produced  in  one  portion  of  a  zone 


105 

corresponding  to  the  circumference  of  the  cornea.*  In  one  case 
I  have  found  four  times  in  fifteen  minutes  the  same  rhythm  ex- 
isting in  one  part  of  the  ciliary  muscle.  At  each  of  these  four 
examinations  I  have  found  sixteen  contractions  in  one  minute. 

5.  Spontaneous  Contractions  of  the  Uterus. — I  have  seen 
hundreds  of  times  the  uterus  or  its  cornua,  full  or  empty,  contract- 
ing to  appearance  spontaneously,  after  the  death  of  rabbits  and 
other  animals,  at  a  time  when  the  spinal  cord  had  entirely  lost, 
not  only  its  reflex  power,  but  also  the  power  of  acting  on  mus- 
cles when  directly  excited  by  galvanism,  by  warmth  or  mechani. 
cally.f 

I  have  also  seen  movements  taking  place  in  the  uterus  and  in 
its  cornua,  in  recently  dead  animals,  the  spinal  cord  of  which  I 
had  destroyed  in  all  its  length.  The  same  movements  I  have 
found  after  I  had  taken  out  from  the  abdomen  of  a  living  animal 
the  whole  uterine  apparatus.  I  have  found  sometimes  that  after 
I  had  put  a  ligature  around  the  trachea  of  guinea  pigs,  which 
were  at  the  end  of  gestation,  parturition  took  place  and  was  pro- 
duced by  three  causes :  1st,  a  direct  excitation  of  the  spinal  cord 
by  the  venous  blood ;  2d,  a  direct  excitation  of  the  uterus  by  that 
blood ;  3d,  a  reflex  action  of  the  spinal  cord.  In  two  cases  I 
have  seen  delivery  taking  place  after  the  action  of  one  only  of 
these  three  cases,  namely,  the  direct  influence  of  black  blood  on 
the  uterus  of  the  Guinea  pigs,  the  spinal  cord  of  which  I  had  de- 
stroyed from  the  sixth  costal  vertebra  to  the  sacrum.  The  more 
complete  and  sudden  is  the  asphyxia,  in  a  rabbit  or  a  Guinea  pig, 
during  labor,  the  more  certain  will  the  delivery  take  place. 

Dr.  Tyler  Smith  speaks  of  a  peristaltic  action  of  the  uterus, 
which  may  expel  the  child  when  the  mother  has  died  during  la- 
bor, undelivered.  He  has  not  attempted  at  all  to  explain  that  con- 

*  The  eyes  had  not  been  opened. 

-|-Dr.  Tyler  Smith,  in  his  very  original  book  on  Parturition,  (London, 
1849,  p.  40,)  says  that  "a  slow  reflex  action  of  the  uterus  may  possibly  con- 
tinue long  after  the  rhythmic  respiratory  actions  have  ceased  ;  as  long,  in- 
deed, as  the  body  retains  its  warmth."  There  is  a  great  error  in  these  lines, 
about  the  relation  between  the  warmth  of  the  body  and  reflex  action.  We 
may  observe  reflex  actions  even  in  animals  that  have  lost  10,  12  or  15°  Cents., 
(18,  22  or  27°  Fahr.,)  of  their  temperature,  and,  in  certain  circumstances, 
these  actions  may  be,  then,  more  powerful  than  if  the  temperature  of  the 
body  was  normal.  For  instance,  if  we  decapitate  an  animal  after  having 

9 


106 

traction,  i.  e.  to  find  out  its  cause  and  the  circumstances  which 
favor  or  are  opposed  to  its  existence  ;  besides,  he  has  not  demon- 
strated that  the  peristaltic  contraction  is  entirely  independent  of 
the  nervous  system. 

6.  Spontaneous  rhythmical  movements  in  the  crop  and  oeso- 
phagus of  pigeons  and  other  birds. — I  have  found  that  if  the  crop 
of  a  bird,  and  more  particularly  of  a  pigeon,  is  opened  during 
digestion,  some  rhythmical  movements  are  frequently  seen  in  it 
and  in  the  oesophagus.  Ordinarily  these  movements  are  perfectly 
regular.      They  begin  in  the  upper  part  of  the  crop,  and  are  pro- 
pagated from  there  to  the  oesophagus.     If  the  animal  is  asphyx- 
iated, these  contractions  become  very  energetic.   Their  ordinary 
number,  in  a  minute,  varies  from  ten  to  twenty. 

I  have  ascertained  that  these  rhythmical  movements  take 
place  as  well  in  a  crop  and  oesophagus  separated  from  the  animal, 
as  in  these  same  parts  left  in  situ.  Therefore,  the  nervous  cen- 
tres are  not  the  source  from  which  originates  the  excitation  which 
acts  on  the  muscular  fibres  to  put  them  in  contraction. 

7.  Spontaneous  movements  in  limbs  of  persons  who  have  died 
of  cholera. — It  is  known  that  after  death  by  cholera,  the  whole 
body,  and  more  particularly  the  limbs,  have  sometimes  very  con- 
siderable  movements.     In  some  cases  I  have  seen  alternative 
movements  of  flexion  and  extension  of  the  arms  or  of  the  legs, 
even  three  hours  after  the  cessation  of  the  beatings  of  the  heart. 
Physicians  who  know  how  quickly  after  death  the  nervous  system 
loses  its  vital  powers,  will  admit  easily  that  these  movements  can- 
not be  the  result  of  an  action  of  that  system.  I  have  ascertained 
on  more  than  sixty  bodies  of  men  who  died  of  cholera,  or  of 
various  other  diseases,  that  a  short  time  before,  or  a  very  short 
time  after  the  cessation  of  the  beatings  of  the  heart,  no  reflex 

put  a  ligature  around  the  carotid  and  vertebral  arteries,  we  find,  when  pul- 
monary insufflation  is  made  carefully,  that  two  important  phenomena  take 
place — one  is  a  gradual  rapid  loss  of  temperature,  if  the  atmosphere  is  cold, 
(this  is  the  well  known  fact  discovered  by  Sir  B.  Brodie,)  and  the  other  is  a 
gradual  and  considerable  increase  of  the  reflex  faculty.  It  has  been  in 
such  cases  that  I  have  found  the  greatest  degrees  of  reflex  power  in  mam- 
mals. The  nervous  power  accumulates  to  such  an  extent  in  the  spinal  cord, 
that  if  we  pinch  the  skin  in  any  part  of  the  body,  but  more  particularly  on 
the  chest  and  on  the  anterior  limbs,  a  reflex  respiratory  movement  takes 
place. 


107 

action  was  produced  by  the  tickling  of  the  sole  of  the  foot.  The 
greatest  duration  of  reflex  action  that  I  have  observed  after  death 
has  been  in  a  case  of  cerebral  apoplexy.  It  has  lasted  thirteen 
minutes  after  the  last  breathing,  and  about  eight  minutes  after 
the  last  beating  of  the  heart.  Dr.  Bennet  Dowler  has  recorded 
many  curious  facts  (observed  in  cases  of  death  from  yellow-fever, 
cholera,  etc.,)  from  which  he  concludes  also  that  the  movements 
taking  place  in  the  limbs  are  not  reflex  actions. 

I  have  found  that,  in  general,  the  more  sudden  and  complete 
has  been  the  asphyxia  before  death,  by  cholera,  the  more  the 
limbs  are  moved  after  death.  I  have  found  also  that  it  is  in  pa- 
tients who  have  died  during  the  algid  period  that  these  move- 
ments are  ordinarily  found. 

These  facts,  as  I  will  show  hereafter,  appear  to  prove  that 
these  movements,  like  the  other  movements,  of  which  I  have 
previously  spoken,  are  excited  by  carbonic  acid  alone,  or  toge- 
ther with  the  poison  of  cholera. 

8.  Spontaneous  contractions  of  the  bowels,  the  bladder,  the  iris 
and  other  parts  of  the  body. — It  is  known  that  frequently  at  the 
time  of  death,  many  of  the  contractile  tissues  of  the  body  are 
put  into  contraction.  I  can  go  farther  and  say  that  it  is  so  with 
all  the  contractile  tissues ;  and  that,  contrary  to  the  general 
opinion,  a  nervous  action  is  not  necessary  for  these  contractions. 

There  are  contractions  in  all  the  following  organs  or  tissues 
during  agony  and  after  death  :  1,  the  muscles  of  animal  life  ; 
2,  the  sphincter  of  the  anus  ;  3,  the  respiratory  muscles ;  4,  the 
iris  ;  5,  the  digestive  canal  (in  all  its  length) ;  6,  the  urinary 
bladder ;  7,  the  uterus ;  8,  the  scrotum,  (dartos) ;  9,  the  gall- 
bladder;  10,  the  ureters;  11,  the  seminal  vesicles;  12,  the 
bronchial  tubes ;  13,  the  skin ;  14,  the  blood-vessels ;  15,  the 
lymphatics  ;  16,  the  cilia. 

As  to  the  skin,  in  many  cases  the  so-called  goose-flesh  (cutis 
anserina)  takes  place  a  little  before  or  little  after  death,  although 
the  body  has  not  yet  become  cold.  I  have  seen  it  vejy  strongly 
marked  on  the  inferior  limbs  of  a  paraplegic  who  died  of  a  soften- 
ing of  the  dorso-lumbar  part  of  the  spinal  cord.  It  results  from 
this  fact  that  the  cellular  tissue  is  able  to  contract  from  the  same 


108 

cause  which  produces  contractions  at  the  time  of  death,  in  mus- 
cular tissues — that  is,  very  likely,  carbonic  acid.* 

Besides,  I  have  found  contractions  of  the  cellular  tissue  of  the 
skin  of  the  face,  in  animals  killed  by  asphyxia,  and  on  which  the 
facial  nerve  had  been  divided  for  many  days  or  weeks. 

In  the  same  man  who  had  a  paraplegia,  and  of  whom  I  have 
just  spoken,  I  saw  very  strong  contractions  in  the  dartos,  during 
agony. 

In  animals  suddenly  asphyxiated,  after  the  destruction  of  the 
dorso-lumbar  part  of  the  spinal  cord,  the  seminal  vesicles  some- 
times contract,  and  a  slow  ejaculation  takes  place,  although  there 
is  no  erection. 

In  the  sphincter  of  the  anus,  when  it  is  paralysed,  there  are 
only  slight  contractions,  but  they  are  evident. 

The  urinary  bladder,  during  agony  or  after  death,  sometimes 
contracts  so  much,  even  when  it  is  paralysed,  that  all  the  urine 
it  contains  is  expelled. 

The  ureters  present  very  strong  contractions,  in  animals 
recently  killed  by  asphyxia,  and  these  contractions  in  some  cases 
are  rhythmical.  The  same  movements  are  seen  when  all  the 
urinary  apparatus  is  in  situ,  and  when  it  has  been  removed  from 
the  abdomen,  and  therefore  separated  from  the  nervous  centres. 
The  contraction  begins  at  the  kidney  and  thence  is  very  quickly 
propagated  all  along  the  ureters  to  their  termination  in  the  blad- 
<der.  Among  the  contractile  tissues,  that  of  the  ureters  is  one 
•of  the  most  irritable. 

Bidder  and  Schmidt,  of  Dorpat,  have  recently  found  that  after 
the  division  of  the  two  pneumogastric  nerves,  there  is  more  car- 
bonic acid  expelled  by  the  lungs  than  usual.  This  fact  is  very 

*  Kolliker  has  recently  discovered  fibro-muscular  cells— that  is,  mus- 
cular fibres  of  organic  life — in  the  skin,  and  he  maintains  that  the  cutis 
<ansertna  is  produced  by  these  fibres,  and  not  by  the  cellular  fibres.  I  have 
published  facts  which,  I  think,  prove  conclusively  that  the  contractions  in 
the  skin  are  in  a  great  measure  performed  by  the  cellular  tissue.  (See 
Oomptes  Rendus  de  la  Soc.  de  Biologic,  1849,  t.  i.  pp.  134  et  157,  et  1850, 
t,  ii.  p.  132.)  Since  that  time,  I  have  found  that  in  some  cartilaginous 
fishes,  in  which  the  iris  does  not  contain  any  muscular  fibre,  and  is  com- 
posed of  cellular  tissue,  this  membrane  may  be  the  seat  of  considerable 
contractions  ;  so  that  I  consider  it  as  perfectly  certain  that  the  cellular  tissue 
/at  least  in  some  organs)  is  contractile. 


109 

important,  because  if  the  theory,  which  I  am  about  to  propose, 
be  true,  we  ought  to  see  a  contraction  produced  in  the  bronchial 
tubes,  in  consequence  of  the  unusual  amount  of  carbonic  acid 
that  they  contain.  Now,  such  a  contraction  certainly  exists  then, 
and  it  is  it  which  causes  the  well-known  difficulty  in  the  expan- 
sion of  the  chest,  which  exists  in  that  case. 

In  the  eyes,  even  when  they  are  paralysed  by  the  section  of 
the  three  nerves  of  the  iris,  (the  third  pair,  the  sympathetic,  in 
the  neck,  and  the  ophthalmic  nerve,)  the  pupil  may,  at  first,  con- 
tract and  afterwards  dilate  very  much. 

The  lymphatics  and  the  thoracic  duct  contract  very  much  after 
death.  I  have,  sometimes,  in  cases  where  these  vessels  were 
dilated  by  chyle,  introduced  a  glass  tube,  two  lines  in  diameter, 
into  the  thoracic  duct,  and  I  have  seen  the  liquid  ascend  into  the 
tube,  and  in  one  case  run  out,  although  the  tube  was  five  inches 
high. 

The  cilia  are  known  to  have  movements  independent  of  the 
nervous  system. 

The  gall-bladder  contracts  little  and  slowly,  but  evidently, 
after  death,  even  when  it  has  been,  with  the  liver,  removed  from 
the  abdomen  and  separated  from  the  nervous  centres. 

The  choledoch  duct  and  the  pancreatic  duct,  as  my  friend  CI. 
Bernard  has  discovered,  have  rhythmical  contractions  during  life, 
in  birds.  I  have  found  these  movements  perfectly  regular  after 
I  had  removed  all  the  viscera  from  the  abdomen.  Therefore  the 
cause  of  these  rhythmical  contractions  is  not  in  the  nervous 
centres. 

The  bowels  have  considerable  contractions  during  agony  and 
after  death ;  and  I  will  prove  hereafter  that  the  cause  of  these 
movements  is  not  the  influence  of  cold,  or  that  of  air,  when  they 
are  exposed  to  the  atmosphere.  Nurses,  in  France,  are  in  the 
habit  of  judging  that  death  has  positively  taken  place,  when, 
after  the  cessation  of  breathing,  they  see  urine  and  foecal  matters 
expelled.  This  expulsion  depends  upon  the  contractions  then 
taking  place  in  the  bladder  and  in  the  bowels. 

9.  Causes  of  the  apparently  spontaneous  contractions  during 
life  and  after  death. — All  the  contractions  of  which  I  have 
spoken,  appear  to  me  to  be  produced  by  an  excitation  made  upon 
the  contractile  tissues  by  a  substance  existing  in  the  blood,  and 


110 

the  quantity  of  which  becomes  much  increased  during  asphyxia. 
The  relations  between  these  contractions  and  asphyxia  are  evi- 
dent. A  great  many  of  them  do  not  exist  unless  asphyxia 
exists,  and  their  energy  is  always  in  proportion  to  the  degree  of 
asphyxia. 

I  believe  that  the  substance  in  the  blood  which  has  that  power 
is  the  carbonic  acid.  In  admitting  this  opinion  we  can  easily 
explain  all  the  phenomena. 

There  are  certain  contractions  which  take  place  in  muscles  of 
animal  life,  after  death,  and  which  have  quite  another  cause.  In 
the  cold  seasons,  it  is  not  uncommon  to  find,  in  limbs  of  frogs, 
when  we  separate  them  from  the  body,  apparently  spontaneous 
contractions,  lasting  sometimes  for  half  an  hour  or  even  more  ; 
but  these  contractions  have  begun  when  we  have  cut  the  nerves, 
and  they  continue  on  account  of  galvanic  discharges  which  ac- 
company them.  The  fact  that  they  begin  after  the  excitation  of 
a  nerve,  is  sufficient  to  show  that  they  are  not  like  the  other  con- 
tractions, of  which  I  have  previously  spoken. 

Some  of  the  facts  I  have  related  may  appear  to  be  distinct 
from  the  others.  So,  for  instance,  contraction  taking  place  in 
paralysed  muscles  of  the  face  or  of  the  limbs  in  living  animals, 
might  be  considered  as  quite  different  from  the  contractions  exist- 
ing after  death.  I  think  that  they  originate  from  the  same  cause, 
viz.,  an  excitation  by  carbonic  acid.  A  muscle  may  be  moved 
or  not  be  moved  by  an  excitant.  If  the  degree  of  irritability  is 
greater  in  one  case  than  in  another,  we  may  see  the  same  amount 
of  excitation  produce  a  movement  in  the  first  case,  and  not  in  the 
second.  If  the  amount  of  excitation  increases,  then  we  may  see 
both  muscles  moved,  but  the  most  irritable  more  than  the  other. 
This  is  sufficient  to  explain  why  the  paralysed  muscles  may  be 
moved  by  the  carbonic  acid  existing  in  the  blood  during  life, 
while  the  muscles  that  are  not  paralysed  are  not  moved.  I  have 
found  that  the  degree  of  irritability  increases,  during  a  certain 
time  after  paralysis,  in  the  muscles  of  animal  life.  Their  irrita- 
bility being  augmented,  they  are  excited  sufficiently  to  contract, 
by  a  quantity  of  carbonic  acid  which  is  not  sufficient  to  act  on 
the  other  muscles. 

The  following  facts  and  reasonings  will,  I  believe,  prove  that, 
at  least  in  the  bowels,  black  blood,  very  likely  by  its  carbonic 


Ill 

acid,  may  excite  powerful  movements.  It  is  known  that  when 
we  open  the  abdomen  of  an  animal  immediately,  or  a  short  time, 
after  death,  we  generally  see  considerable  movements  in  the 
bowels.  These  movements  have  been  attributed  to  the  action  of 
air,  or  to  that  of  cold,  on  the  bowels.  This  is  not  a  right  view. 
A  sudden  exposure  to  a  cold  atmosphere  may,  possibly,  produce 
contractions  in  the  bowels ;  but  certainly  cold  is  not  the  ordinary 
cause  of  these  movements.  At  first,  they  may  exist  in  a  warm 
atmosphere,  and  then  they  appear  to  be  more  rapid  than  in  a 
cold  atmosphere.  Besides,  the  bowels  may  be  exposed  to  a  cold 
atmosphere,  and  remain  motionless,  although  they  have  their  en- 
tire irritability.  As  to  atmospheric  air,  it  is  not  able  to  excite  a 
movement  in  the  bowels.  If  we  open  the  abdomen  of  a  living 
animal,  in  avoiding  to  excite  mechanically  the  bowels,  and  in  al- 
lowing the  animal  to  breathe  freely,  we  may  for  a  long  time  see 
no  other  movement  in  the  bowels,  except,  sometimes,  slight  re- 
gular and  natural  peristaltic  motions,  depending  on  digestion, 
and  limited  to  some  small  parts  of  the  bowels.  The  animal  must 
be  kept  on  his  back,  and  we  must  avoid  touching  the  bowels,  be- 
cause a  slight  contact  is  sufficient  to  produce  movement.  Now, 
if  we  prevent  the  animal  from  breathing,  we  see,  after  ten,  fif- 
teen, or  twenty  seconds,  very  violent,  sudden,  and  rapid  contrac- 
tions taking  place  in  all  parts  of  the  intestine,  from  the  stomach 
to  the  rectum,  but  much  more  in  the  small  intestine  than  else- 
where. These  movements  are  quite  different  from  the  digestive 
peristaltic  movements.  If  the  animal  is  allowed  to  breathe  again, 
and  freely,  the  movements  diminish  gradually,  and  disappear 
almost  entirely  after  a  few  minutes.  Then,  if  we  prevent  it 
again  to  breathe,  we  see  the  movements  produced  again.  This 
experiment  may  be  repeated  many  times,  with  the  same  result, 
on  the  same  animal. 

We  are  certainly  entitled  to  conclude  that  there  is  an  exciting 
cause  of  contractions,  developed  during  asphyxia,  and  that  it  is 
neither  the  cold  nor  the  atmospheric  air  which  produces  in  all 
cases  the  movements  of  the  bowels  after  the  opening  of  the  abdo- 
men. We  may  draw  the  same  conclusions  from  another  experi- 
ment. If  we  put  a  tie  around  the  trachea  of  a  living  animal, 
immediately  after  expiration,  we  may  see  and  feel  violent  move- 
ments taking  place  in  the  bowels,  although  the  abdomen  is  not 


112 

opened.  It  is  in  consequence  of  such  movements  that  there  is 
an  expulsion  of  faecal  matters,  after  death,  in  man.  The  urine 
may  be  also  expelled  in  these  cases,  in  man  and  in  animals,  and 
this  expulsion  takes  place  because  the  bladder  contracts,  and  not, 
as  it  is  generally  admitted,  because  the  sphincter  vesicce  becomes 
relaxed. 

Some  physiologists  have  considered  the  cessation  of  the  circula- 
tion of  the  blood  in  the  bowels  as  the  cause  of  their  movements, 
after  death,  and  they  relate  as  a  proof  the  fact  that  the  section  of 
one  of  the  arteries  going  to  a  part  of  the  intestines,  is  followed  by 
contractions  in  the  parts  thus  deprived  of  circulation.  But  no- 
thing is  explained  by  saying  that  the  cause  of  the  contraction  is 
in  the  absence  of  circulation.  As  contractions  require  an  exci- 
tation to  be  produced,  what  is  the  exciting  cause  when  the  blood 
does  not  circulate  ?  After  the  section  of  an  artery  there  is  blood 
remaining  in  the  capillaries,  and  that  blood,  after  a  short  time,  be- 
comes very  rich  in  carbonic  acid,  and  then,  if  my  theory  is  right, 
contractions  ought  to  be  produced.  The  result  of  the  section  of 
one  of  the  arteries  is,  therefore,  in  accordance  with  my  theory. 

Other  facts  may  be  adduced  proving  the  influence  of  black 
blood  and  carbonic  acid  on  the  bowels. 

If  black  blood  is  injected  in  the  arteries  of  the  small  intestine 
when  its  irritability  is  much  diminished,  movements  are  almost 
immediately  produced,  but  they  do  not  last  long.  On  the  con- 
trary, if  red  blood  is  injected,  movements  do  not  appear  immedi- 
ately, and  they  are  very  strong  and  last  long.  This  action  of 
red  blood  may  be  easily  understood :  it  increases  the  irritability 
of  the  muscular  layer  of  the  bowels,  as  it  does  for  that  of  the 
muscles  of  animal  life,  and  when  it  has  been  changed  into  black 
blood,  it  excites  the  muscular  tissue  and  produces  contraction. 
The  strength  and  the  long  duration  of  the  contraction  in  this 
case  depend  on  the  increase  of  irritability.  When,  as  in  the 
above  experiment,  black  blood  (containing  a  great  quantity  of 
carbonic  acid,  on  account  of  the  constant  formation  of  that  gas 
in  blood  deprived  of  the  contact  of  atmospheric  air)  is  injected, 
the  irritability  is  not  sensibly  increased,  but  the  excitation  is  con- 
siderable and  there  is  an  almost  immediate  effect. 

If  air  is  injected  in  the  arteries  of  the  bowels,  soon  after  the 
death  of  the  animal,  a  part  of  the  blood  it  contains  is  expelled, 


113 

and  we  find  that  the  movements  do  not  last  as  long  as  if  the 
blood  had  not  been  removed. 

When  an  animal  is  killed  by  haemorrhage,  the  intestine,  as  well 
as  all  the  other  organs,  contains  more  blood  than  usual,  and  then 
its  movements  are  not  so  strong,  and  last  less  than  they  do  gene- 
rally. 

When  in  a  recently  asphyxiated  animal  the  arteries  and  veins 
of  a  part  of  the  bowels  are  divided,  the  movements  of  that  part 
become  less  strong  and  last  less  than  those  of  the  other  parts  of 
the  intestine. 

When  the  bowels  of  a  recently  asphyxiated  animal  are  put 
under  a  receiver  containing  carbonic  acid,  their  movements  are 
very  much  increased,  but  they  do  not  last  so  long  as  when  they 
are  in  the  atmosphere. 

When  they  are  put  under  a  receiver  containing  hydrogen, 
their  movements  are  very  quickly  diminished  in  strength,  and 
they  last  still  less  than  when  exposed  to  carbonic  acid. 

When  they  are  put  in  oxygen,  their  movements  diminish  a 
little  at  first  and  soon  after  become  stronger,  and  they  last  much 
longer  than  usual. 

As  a  general  conclusion  about  the  apparently  spontaneous  con- 
tractions which  I  have  described  as  taking  place  in  paralyzed 
muscles  during  life  or  after  death,  I  will  say  that  it  seems  that 
black  blood  by  its  carbonic  acid  is  the  cause  of  these  contractions. 
When  the  nervous  centres  are  still  united  with  the  contractile 
tissues,  we  see,  during  agony  or  after  death,  stronger  movements 
generally  than  when  they  are  separated.  The  action  of  black 
blood  on  the  nervous  centres  may  be  very  great.  I  have  found 
that  the  spinal  cord,  when  separated  from  the  encephalon,  may 
be  strongly  excited  by  black  blood.  If  an  animal  is  asphyxiated 
after  a  transversal  and  complete  division  of  its  spinal  marrow  in 
the  dorsal  region,  we  see  convulsions  taking  place  in  the  poste- 
rior limbs,  and  they  are  nearly  as  strong  as  when  the  nervous 
centers  have  not  been  injured.  The  excitation  on  the  spinal 
marrow  is  considerable  enough  to  produce  an  erection  of  the 
penis.* 

*  Almost  all,  if  not  all,  the  secretions  of  the  body  are  increased  during 
asphyxia:  bile,  (as  shown  by  Professor  Bouisson,)  saliva,  tears,  gastric, 
pancreatic  and  intestinal  juices,  and  also  liver-sugar,  etc.,  are  produced  in 


114 


XXXIV. — ON  THE   CAUSE   OF   THE   BEATINGS   OF  THE   HEART. 

The  cause  of  the  rhythmical  movements  of  the  heart  has  been 
heretofore  unknown.  I  believe  I  have  discovered  it. 

Before  exposing  my  theory  and  the  facts  upon  which  it  is 
grounded,  I  will  show  that  the  theories  put  forward  until  now 
are  not  correct. 

There  are  three  theories  only  which  are  worthy  of  examina- 
tion :  1st,  that  of  Haller ;  2d,  that  of  Carpenter ;  3d,  that  of 
Budge,  Schiff,  and  others. 

Haller  has  been  very  near  the  truth  in  admitting  that  the 
beatings  of  the  heart  were  excited  by  the  blood.  His  error  has 
been  an  error  loci.  He  thought  that  the  blood  acted  in  the 
cavities  of  the  heart.  It  is  not  so ;  and  it  is  known  that  the 
heart  may  continue  to  beat  after  all  the  blood  has  been  drawn 
out  of  its  cavities. 

The  doctrine  of  Carpenter*  is  a  very  simple  and  remarkable 
one.  He  believes  that  the  muscular  fibres  may  act  without  hav- 
ing been  excited.  A  muscle,  says  he,  may  be  compared  to  the 
electric  jar,  and  become  so  charged  with  motility ,  (or  motor  force,) 
as  to  execute  spontaneous  contractions ;  and  elsewhere,  "  It  is  not 
very  difficult  to  conceive  that  the  ordinary  rhythmical  movements 
of  the  heart  may  be  due  to  a  simple  excess  of  this  motility,  which 
is  continually  being  supplied  by  the  nutritive  operations,  and  is 
as  constantly  discharging  itself  in  contractile  action."  Carpenter 
believes  that  the  reason  for  which  the  heart  presents  spontaneous 
contractions  while  the  other  muscles  do  not,  (at  least  ordinarily,) 
is,  that  there  is  a  higher  degree  of  motility  in  the  heart.  He 
considers  as  very  important  the  facts  I  have  discovered,  that 
many  other  muscles  besides  the  heart  may  present  rhythmical 
movements.  He  thinks  that  these  facts  show  there  is  a  tendency 
to  rhythmical  movements  in  the  muscles  themselves,  altogether 

greater  quantity  then  than  usual.  I  believe  that  this  increase  results  from 
the  excitation  of  the  nervous  system,  and,  in  some  measure,  perhaps,  from 
a  direct  action  of  black  blood  on  the  capillaries  of  the  glands.  The  urinary 
secretion  may  also  be  changed  in  asphyxia,  and  not  only  then  the  urine 
may  contain  sugar,  as  Alvaro  Reynoso  has  found,  but  also  albumen. 

*See  his  Principles  of  Human  Physiology,  American  edition,  by  F.  G. 
Smith.  Philadelphia,  1853.  pp.  130  to  132,  319,  325,  and  471-72. 


115 

independent  of  the   excitement   to   action  which   they  receive 
through  the  nervous  system. 

The  best  ground  for  the  hypothesis  of  Carpenter  is  that,  ac- 
cording to  him,  the  heart  continues  to  heat,  although  it  is  not 
exposed  to  any  excitation  in  certain  circumstances.  He  says : 
"When  every  source  of  excitement  is  excluded,  we  cannot  but 
perceive  that  these  actions  take  place  with  a  spontaniety  which 
can  scarcely  be  accounted  for  in  any  other  way  than  by  con- 
sidering them  as  expressions  of  the  vital  activity  of  the  compo- 
nent cells  of  these  forms  of  muscular  tissue,  which  manifests  it- 
self in  this  mode,  when  the  developmental  life  of  the  cell  has  at- 
tained its  maturity.  And  this  view  is  strikingly  confirmed  by" 
what  we  know  of  the  origin  and  termination  of  these  movements. 
For  the  action  of  the  heart  commences  when,  as  yet,  its  contrac- 
tile parietes  consist  but  of  an  assemblage  of  ordinary-looking 
cells,  no  proper  muscular  tissue  being  evolved,  and  no  nervous 
system  being  yet  developed,  from  which  the  stimulus  to  the  move- 
ment can  proceed ;  and  it  is  impossible  to  assign  any  other  cause 
for  the  movement  under  such  circumstances,  than  the  attributes 
inherent  in  the  tissues  which  perform  it." 

The  first  thing  to  be  said  against  the  view  of  Carpenter  is,  that 
his  hypothesis  is  not  necessary ;  because  it  is  possible  to  assign 
another  cause  for  the  movement  of  the  heart  under  the  circum- 
stances he  speaks  of.  This  will  be  proved  hereafter. 

The  doctrine  of  Carpenter  implies,  that  the  degree  of  irrita- 
bility (motility,  motor  force,  contractility, — never  mind  the 
name)  is  greater  in  the  heart  than  in  the  other  muscles  which 
have  no  spontaneous  action.  This  is  not  the  case.  The  degree 
of  irritability,  as  judged  by  its  duration  after  death,  is  generally 
greater  in  the  muscle  of  animal  life,  than  in  the  heart.  The  ac- 
cepted sentence  of  Haller,  Cor  ultimum  moriens,  generally,  is 
not  true. 

If  Carpenter  was  right,  we  should  see,  during  life,  the  appa- 
rently spontaneous  contractions  which  take  place  in  all  the  con- 
tractile tissues  after  death ;  because  their  irritability  is  at  a 
higher  degree  in  the  first,  than  in  the  second  case.  Besides,  we 
should  not  see  oxygen,  or  red  blood,  diminish  the  frequency  of 
the  beatings  of  the  heart ;  and  black  blood,  or  carbonic  acid,  in- 
crease that  frequency. 


116 

An  experiment,  consisting  in  the  research  of  the  influence  of 
vacuo  on  the  heart,  has  been  made  by  Tiedemann  and  by  Dr. 
S.  W.  Mitchell,  and  Dr.  T.  H.  Bache,  (see  Dunglison's  Physiol., 
vol.  ii.  p.  150.)  It  seems  to  me  that  the  result  of  this  experi- 
ment is  in  complete  opposition  to  the  doctrine  of  Carpenter. 
These  experimenters  have  found  that  the  beatings  of  a  heart  were 
speedily  brought  to  a  stand  by  the  exhaustion  of  the  air,  and 
that  they  were  renewed  when  it  was  re-admitted.  If  the  view 
of  the  eminent  British  physiologist  was  right,  we  ought  to  see 
the  heart  continue  to  beat  in  vacuo  about  the  same  length  of  time 
as  it  would  in  hydrogen  or  nitrogen,  because  its  irritability 
•cannot  be  suddenly  diminished  enough  by  the  exhaustion  of  the 
air.  In  these  gases  the  heart  of  a  mammal  may  beat  for  five  or 
ten  minutes  or  more,  and  the  right  auricle  may  beat  for  hours ; 
and  the  heart  of  a  frog  may  beat  for  one  day.  It  is  much  more 
to  account  for  the  stopping  of  the  heart's  action  in  admitting  that 
the  excitant  of  that  action  is  removed  during  the  exhaustion  of 
the  air.  John  Reid  had  found  that  the  heart  of  a  frog  had  con- 
tinued to  beat  in  vacua,  but  how  long  he  does  not  say.* 

I  will  relate  hereafter  many  experiments  of  mine  which  are  in 
opposition  to  the  theory  of  Carpenter. 

It  is  one  of  the  most  important  questions  in  physiology,  whether 
the  nervous  centres,  the  nerves,  and  the  contractile  tissues  are 
able  to  act  without  stimulation.  This  question  has  not  been 
yet  entirely  treated  by  any  physiologist.  I  propose  publishing 
a  special  paper  on  the  subject.  I  will  merely  say  here  that  there 
may  be  apparently  spontaneous  actions  in  the  spinal  cord,  as  well 
as  in  the  muscles.  For  instance,  very  frequently,  in  a  frog,  after 
the  removal  of  the  brain  and  the  medulla  oblongata,  we  may  see 
strong  movements  apparently  spontaneous,  but  when  we  know 
that  the  slightest  excitation  of  the  skin,  or  of  any  other  very  sen- 

*  Art.  Heart,  in  Todd's  Cyclop.,  vol.  ii.  p.  611.  J.  Reid  says  in  the  same 
page,  "We  ought  to  be  more  cautious  in  admitting  the  existence  of  this  in- 
nate moving  power,  since  it  is  in  opposition  to  a  well  known  law  in  the 
animal  economy,  that  though  the  various  tissues  of  an  organised  body  are 
endowed  with  certain  vital  properties,  yet  the  application  of  certain  exter- 
nal and  internal  stimuli  is  necessary  to  produce  their  manifestations  of 
activity.  In  fact  it  is  from  the  action  and  reaction  of  these  tissues  and 
excitants  upon  each  other  that  the  phenomena  of  life  result." 


117 

sitive  part,  may  excite  the  spinal  cord,  and  produce  a  reflex  ac- 
tion, we  are  authorised  to  consider  all  the  movements  taking  place 
as  reflex  actions.  An  excitation  may  have  come  to  the  spinal 
marrow  from  the  bladder,  from  the  bowels,  from  the  lungs,  (in 
which  worms  are  almost  always  found  in  the  cold  seasons,  i.  e. 
at  the  time  these  phenomena  are  generally  observed,)  etc. 

As  to  the  spontaneity  of  action  in  muscles,  I  have  tried  to 
prove  ia  a  preceding  article  that  it  is  a  mere  and  false  appear- 
ance.* I  will  prove  hereafter  that  the  cause  of  the  apparently 
spontaneous  contractions  of  the  heart,  is  the  same  as  that  of  the 
like  contractions  in  other  contractile  tissues. 

The  physiologists  who  maintain  that  the  beatings  of  the  heart 

*  Carpenter  says  that  the  action  of  the  uterus,  as  it  shows  itself,  "  not 
merely  in  the  final  parturient  effort,  but  in  local  contractions  that  frequently 
occur  during  the  latter  months  of  gestation,  (simulating  the  movements  of 
the  foetus,)  are  more  satisfactorily  accounted  for  by  considering  them  as  a 
discharge  of  accumulated  power,  than  in  any  other  mode."  I  will  try  to 
prove  elsewhere  that  for  the  uterus,  as  well  as  for  any  other  contractile 
tisue,  there  is  no  spontaneous  action.  The  uterus,  in  pregnancy,  becomes 
more  and  more  irritable  every  day,  and  when  its  irritability  has  arrived  at 
a  very  high  degree,  then  the  slight  excitation  produced  by  the  carbonic 
acid  normally  contained  in  the  blood  is  sufficient  to  put  it  in  action.  When 
the  contractions  have  begun,  they  are  very  much  increased  by  a  reflex  ac- 
tion. Every  contraction  is  accompanied  by  a  galvanic  discharge  on  the 
nerves  in  the  neighborhood  of  the  muscular  fibres  which  contract,  and  the 
sensitive  nerves  being  thus  excited,  it  results,  1st,  that  a  pain  is  felt,  the 
degree  of  which  is  in  proportion  to  the  degree  of  any  contraction,  and 
therefore  with  the  degree  of  galvanic  discharge  ;f  2d,  that  the  spinal  mar- 
row is  excited,  and  produces  reflex  movements  in  the  uterus.  Now,  the 
more  these  reflex  contractions  are  energetic,  the  more  they  are  induced  to 
take  place  again,  on  account  of  the  galvanic  discharge  which  accompanies 
them.  So  that  there  would  be  a  constant  increase  in  the  intensity  of  the 
contractions  if  there  were  not  four  limits  to  them.  1st,  there  is  no 
galvanic  discharge  when  the  muscular  fibres  are  contracted;  it  is  only 
at  the  time  they  are  contracting  that  this  discharge  takes  place ;  2d,  the 
primitive  cause  of  contraction,  the  excitation  of  the  muscular  tissue,  by  car- 
bonic acid,  diminishes  much  during  the  contraction,  because  the  caliber  of 
the  small  blood-vessels  is  much  diminished,  and  the  blood  expelled  from 
them  ;  3d,  every  contraction  of  the  uterus  diminishes  the  degree  of  its  irri- 
tability ;  4th,  the  reflex  power  of  the  spinal  cord  becomes  exhausted,  or  at 
least  diminished. 

t  See,  on  this  subject,  my  paper  in  the  Comptes  rendus  de  la  Soci4te  de  Bologne,  en.  1850,  t.  ii 
p.  172. 


118 

depend  on  the  nervous  system,  appear  to  me  to  be  greatly  mis- 
taken. They  make  a  confusion  between  two  things,  greatly  dis- 
tinct, one  from  the  other :  they  conclude  from  the  fact  that  the 
nervous  system  is  able  to  act  on  the  heart,  that  its  influence  is 
necessary.  It  is  the  same  kind  of  mistake  which  is  so  frequently 
made  as  to  the  influence  of  the  nervous  system  on  nutrition,  on 
secretions,  and  on  animal  heat ;  because  that  system  is  able  to 
act  upon  these  functions,  it  is  concluded  that  its  influence  is  ne- 
cessary. 

The  first  argument  to  be  adduced  against  the  writers  who  ad- 
mit, as  necessary,  the  influence  of  the  nervous  system  on  the 
heart,  is,  that  they  change  only  the  ground  of  the  difficulty  in 
doing  so.  Instead  of  having  to  explain  why  the  heart  acts  rhyth- 
mically, they  have  to  explain  why  the  nervous  system  acts  rhyth- 
mically on  the  heart.  Not  only  they  have  not  explained  this 
rhythmic  action  of  the  nervous  system,  but,  as  far  as  I  know, 
they  appear  not  to  have  been  aware  that  this  was  to  be  explained. 

The  second  reason  I  will  mention,  is  the  fact,  so  well  esta- 
blised  by  my  friend  Professor  Lebert,  that,  in  embryos,  the  heart 
beats  when  it  is  merely  composed  of  cells,  and  when  the  nervous 
system  has  not  yet  appeared 

A  third  reason  is,  that,  either  in  monsters,  or  in  animals  ope- 
rated on  by  physiologists,  there  has  been  a  long  persistence  of  the 
beatings  of  the  heart  when  a  part  of  the  cerebro-spinal  centre  did 
not  exist,  or  had  been  removed.  Any  part  may  be  in  that  case, 
even  the  medulla  oblongata,  as  I  have  discovered.  (See  Art.  xvi. 
p.  40.) 

In  opposition  to  the  idea  that  the  beatings  of  the  heart  depend 
on  the  microscopical  ganglia  existing  in  that  organ,  I  will  say, 
that,  besides  the  fact  that  the  heart  beats  in  embryos  before  the 
nervous  system  exists,  and  besides  the  improbability  that  such  a 
small  amount  of  nervous  matter  should  have  so  great  a  power, 
there  are  two  good  reasons  against  this  strange  theory : — 
1.  There  have  been  found  no  ganglia,  large  or  microscopical,  in 
the  auricles,  in  the  sinuses  of  the  pulmonary  veins,  or  in  those 
veins.  All  these  parts,  nevertheless,  may  continue  to  beat  a  long 
while,  (even  for  hours,)  after  they  have  been  separated  from  the 
ventricles  where  are  the  microscopic  ganglia.  2.  Rhythmical 
movements  may  exist  in  a'great  many  other  muscular  parts  of  the 


119 

% 

body,  where  there  is  no  microscopical  ganglion,  and  where  these 
parts  have  ceased  to  be  under  the  influence  of  the  nervous  centres. 

The  three  theories  which  I  have  examined  being  unable  to  ex- 
plain the  beatings  of  the  heart,  I  will  now  expose  my  theory, 
and  discuss  the  three  following  questions : — 1.  What  is  the  exci- 
tant which  puts  the  heart  in  action  ?  2.  Does  that  excitant  act 
rhythmically  ?  3.  Does  that  excitant  act  together  directly  on 
the  muscular  fibres  of  the  heart,  and  on  the  nervous  system ;  or 
does  it  act  only  on  the  muscular  fibres  ? 

After  having  solved  these  three  questions,  I  will  examine  the 
objections  which  might  be  made  to  the  doctrine  I  propose. 

1.    What  is  the  excitant  which  puts  the  heart  in  action  ? 

I  believe  that  the  beatings  of  the  heart  are  excited  by  a  prin- 
ciple existing  in  the  blood,  and  that  carbonic  acid  is  that  princi- 
ple. This  view  is  grounded  on  the  following  facts : 

a.  When  we  prevent  a  warm  -blooded  animal  from  breathing,  the 
beatings  of  the  heart  become  more  frequent  than  before,  for  about 
one  or  two  minutes.     It  is  not  on  account  of  the  emotion  alone 
that  it  is  so,  because  the  same  effect  is  produced  when  we  as- 
phyxiate suddenly  an  animal  which  has  entirely  lost  his  power 
of  having  emotions,  in  consequence  of  the  action  of  chloroform. 

b.  Many  times  I  have  found,  on  myself  and  on  one  of  my 
friends,  that  the  beatings  of  the  heart  are  rendered  more  active 
during  asphyxia.     We  hold   our  breath  for  about  three  quar- 
ters of  a  minute,  and  during  the  last  fifteen  seconds  the  heart 
beats  from  two  to  four  (in  one  case  five)  minutes  more  than  when 
the  respiration  was  free.     We  have  made  the  experiment  in  the 
sitting  position,  avoiding  any  movement  of  the  body  in  all  the 
cases. 

c.  John  Reid  has  discovered  that  when  any  hemadynamometer  is 
put  in  the  femoral  artery  of  a  dog,  the  mercury  rises  in  the  in- 
strument if  the  animal  is  asphyxiated,  and  about  one  minute  after 
the  respiration  has  been  stopped.    The  same  result  has  been  ob- 
tained in  twenty  experiments.     It  seems  to  me  that  this  fact 
proves  that  the  contractions  of  the  heart  become  more  energetic 
during  asphyxia.    John  Reid  attributes  the  result  he  has  obtained 
to  some  difficulty  that  black  blood  seems  to  have  in  passing  through 
the  capillaries  of  the  different  parts  of  the  body.    I  do  not  deny 
that  there  is  such  a  difficulty ;  but  I  think  that  the  great  reason 


120 

of  the  ascension  of  mercury  in  the  hemadynamometer  is,  the  in- 
crease in  the  force  of  the  heart.  A  simple  experiment  proves 
that  I  am  right.  I  adapt  the  hemadynamometer  to  the  aorta  in 
the  abdominal  cavity,  and  then  I  open  quickly  the  chest,  and  I 
put  a  ligature  to  the  brachial  and  carotid  arteries.  About  three 
quarters  of  a  minute  after  opening  the  chest,  and  about  half 
a  minute  after  the  ligature  has  been  put  on  the  arteries  of  the 
head  and  arms,  the  mercury  rises  notably  in  the  instrument ; 
sometimes  the  elevation  is  as  considerable  as  two  inches.  It  re- 
sults from  this  experiment,  that  the  heart  beats  more  strongly  in 
asphyxia  about  one  minute  after  its  beginning. 

d.  Woodall,  a  most  intelligent  and  accurate  observer,  says  Dr. 
Martin  Paine,  (see   Med.  and  Physiol.  Comment.,  t.  ii.  p.  49,) 
states,  that  the  best  remedy  for  syncope  is  to  obstruct  respiration 
entirely  by  momentarily  confining  the  nose  and  mouth.     If  this 
be  true,  it  is  in  perfect  accordance  with  my  view,  that,  during  as- 
phyxia, the  normal  cause  of  the  beating  of  the  heart  increases  in 
the  blood. 

e.  If  a  frog  is  put  under  a  receiver  containing  pure  oxygen,  at 
a  temperature  of  40  or  50°  Fahr.  (4,  5,  or  10  Cent.)  after  its 
heart  has  been  laid  bare  and  its  central  nervous  system  destroyed, 
we  see  the  heart  beat  for  a  very  long  time,  (one,  two,  or  three 
days.)     On  the  contrary,  if,  at  the  same  temperature,  another 
frog,  deprived  also  of  the  central  nervous  system,  is  put  in  car- 
bonic acid  gas,  the  heart  beats  very  quickly  at  first,  but  it  soon 
ceases  to  beat,  (in  one  or  two  hours  only,  sometimes,  and  for  the 
most  about  half  a  day.) 

/.  All  the  causes  which  increase  the  formation  of  carbonic  acid 
gas  in  the  body,  increases  the  frequency  of  beatings  of  the  heart. 

g.  If  we  inject  the  serum  of  blood  into  the  arteries  of  the  heart, 
so  as  to  expel  as  completely  as  possible  the  blood  contained  in  the 
capillaries  of  this  organ,  and  if  then  we  remove  the  blood  from 
the  cavities  of  the  heart,  we  find  that  its  beatings  are,  at  once, 
almost  entirely  suspended,  and  that  they  are  completely  stopped 
in  a  very  short  time,  (from  one  to  eight  minutes.)  The  muscu- 
lar irritability  is  not  destroyed  in  this  organ ;  it  does  not  beat 
because  its  excitant  has  been  removed. 

h.  I  have  found  that  when  the  heart  of  a  young  animal  is  put 
in  hydrogen,  its  beatings  hardly  change  at  first,  but  they  stop  in 


131 

a  very  short  time.  When  it  is  put  in  carbonic  acid  gas,  its  beat- 
ings are,  at  first,  increased  in  frequency  and  strength ;  but  they 
very  soon  are  stopped.  When  it  is  put  in  oxygen,  its  beatings 
are  slowly  increased  in  frequency  and  strength,  and  they  last 
very  long. 

i.  On  newly-born  cats  and  dogs,  before  the  occlusion  of  the 
ductus  jarteriosus,  I  open  the  chest  and  put  a  ligature  on  the  ar- 
teries going  to  the  head  and  fore  limbs,  and  on  the  aorta  imme- 
diately after  the  origin  of  the  ductus  arteriosus.  Then  the  blood, 
expelled  from  the  right  ventricle,  is  sent  to  the  lungs,  from  which 
it  comes  to  the  left  auricle,  and  afterwards  to  the  left  ventricle. 
From  there  it  is  sent  into  the  only  part  of  the  aorta  remaining  ac- 
cessible, and  thence  it  goes  into  the  cardiac  arteries,  and  into  the 
pulmonary  artery,  through  the  ductus  arteriosus,  (a  direction  which 
is  the  reverse  of  the  normal  direction  in  that  duct.)  By  the  cardiac 
veins  the  blood  arrives  again  in  the  right  side  of  the  heart.  The 
circulation  from  the  heart  to  the  lungs,  and  vice  versa,  continues 
very  well.  I  have  found,  that  if  hydrogen  is  insufflated  into  the 
lungs,  the  beatings  of  the  heart  are  not  much  changed  at  first, 
but  they  go  on  diminishing,  and  they  disappear  in  a  short  time. 
When  an  injection  is  made  with  carbonic  acid,  the  beatings  of  the 
heart  are  quickly  increased  in  frequency  and  strength ;  but  they 
are  stopped  after  a  short  time.  When  oxygen  is  insufflated,  the 
beatings  of  the  heart  become  slowly  more  frequent,  and  they  re- 
main quick  and  strong  for  a  long  time.  (I  have  once,  by  such 
insufflation  of  oxygen,  maintained  beating  for  eleven  hours  in  the 
heart  of  a  young  cat.) 

I  believe  that  these  facts  prove  that  black  blood,  by  its  car- 
bonic acid,  is  an  excitant  of  the  beatings  of  the  heart.  If,  now, 
we  adduce  to  these  facts  all  those  I  have  related  in  a  preceding 
article,  on  the  apparently  spontaneous  contractions  in  all  the 
contractile  tissues  of  the  body,  we  shall  have  a  very  considerable 
number  of  facts,  proving  that,  during  asphyxia,  there  is  an  ac- 
cumulation in  the  blood  of  the  principle  which  causes  these  con- 
tractions. I  believe  that  it  is  almost  impossible  to  deny  that  this 
principle  is  the  carbonic  acid  gas- 
Before  trying  to  show  that  what  takes  place  in  asphyxia  in 
the  heart  is  only  an  exaggeration  of  what  normally  exists  in  that 
organ,  I  will  treat  the  two  remaining  of  the  three  questions  I 

10 


122 

have  announced  I  would  endeavor  to  solve,  as  regards  the  exci- 
tant of  the  heart's  action. 

2.    Why  does  that  excitant  act  rhythmically  ? 

I  believe  it  is  easy  to  explain  why  the  agent  of  excitation  of 
the  heart*  produces  rhythmical  contractions.  I  will  suppose,  first, 
that  the  action  is  permanent.  A  part  of  the  heart,  ventricles,  or 
auricles,  'being  dilated,  receives  an  excitation  in  all  its  fibres  si- 
multaneously, and  a  contraction  is  produced.  But,  according  to 
the  well-known  law  of  Schwann,  the  exciting  cause  which  is  able 
to  give  the  impulse  when  the  muscular  fibres  are  long,  is  not  able 
to  maintain  the  contraction  when  the  fibres  have  been  shortened. 
Then,  on  account  of  this  insufficiency  of  power  of  the  cause  of  the 
contraction,  a  dilatation  ensues.  We  may  present  the  fact  in 
other  words,  and  say  that  the  resistance  to  the  contraction  origi- 
nating from  the  displacement  of  the  constitutive  matter  of  the 
contractile  tissues,  increases  in  proportion  to  the  shortening  of 
the  fibres ;  and  that  after  the  fibres  have  contracted  under  the 
impulse  of  the  exciting  cause,  although  this  cause  continues  to 
act,  a  dilatation  is  produced  by  the  force  belonging  to  that  re- 
sistance, which  is  nothing  but  elasticity.  If  the  cause  of  the  con- 
traction of  the  heart  was  a  considerable  one,  then  we  should  see 
a  permanent  .contraction ;  and  it  is  so  when  we  apply  galvanism — 
the  elasticity,  then,  is  not  powerful  eno-ugh  to  produce  dilatation. 
On  the  contrary,  with  a  weak  exciting  cause,  like  earbenic  acid, 
the  result  ought  to  be  different.  When  that  cause  has  more 
power,  as  in  asphyxia,  the  shortening  of  the  fibres  takes  place 
quicker,  and  is  more  considerable ;  and  even  then  it  is  not  suffi- 
cient to  maintain  contraction,  the  tendency  to  dilatatioa  being 
also  increased. 

I  ought  to  say,  that  the  excitant  cause  of  the  contractions  is 
not  always  at  the  same  degree  of  power.  The  small  blood-vessels 
and  the  capillaries  being  compressed  diiring  the  muscular  con- 
tractions, there  is  a  diminution  of  excitation  during  that  time. 
This  should  be  sufficient  to  explain  the  alternate  contractions 
and  dilatations.  But  such  a  diminution  in  the  caliber  ought  to 
be  very  little,  if  even  it  exists  in  certain  organs,  (the  heart  when 
composed  of  cells,  for  instance.) 

•*  Whal  I  will  .gay  here  for  the  heart,  might  be  said  for  all  the  .contractile 
tissues,  presenting  apparently  spontaneous  rhythmical  contractions,  as  the 
eiiia,  for  instance. 


123 

I  come  now  to  the  third  question  about  the  excitant  of  the 
heart — 

3.  Does  that  excitant  act  together  on  the  muscular  fibres  and 
on  the  nerves  of  the  heart,  or  does  it  act  only  on  the  muscular 
fibres  ? 

I  believe  at  ought  to  act  also  on  the  nerves ;  but  I  cannot  prove 
it  otherwise  tthan  by  saying,  that  all  the  agents  of  excitation  that 
we  know  to  .act  on  the  muscular  fibres,  are  able  to  act  on  the 
nerves. 

There  are  many  things  to  be  said  besides  the  above  facts  and 
reasoning,  to  prove  the  truth  of  the  doctrine  I  propose.  I  will 
expose  some  of  them. 

The  following  question  might  be  made : 

How  is  it  that  the  heart  is  the  only  muscle  containing  striated 
fibres,  which  presents  normally  rhythmical  movements  ? 

^  The  answer  to  this  question  appears  to  be  very  simple.  The 
intensity  of  the  stimuli,  the  degree  of  irritability,  and  the  resist- 
ance which  a  muscle  has  to  overcome  when  it  contracts,  are  three 
elements  which  we  ought  not  to  lose  sight  of  when  we  examine 
the  difference  of  contractions  between  two  muscles.  Suppose  the 
heart  possessing  the  same  degree  of  irritability  as  another  mus- 
cle :  if  the  stimulus  is  the  same,  and  the  resistance  the  same  also, 
for  the  heart  and  for  the  other  muscle,  there  will  be  the  same 
effects.  But  if  the  stimulus  is  more  considerable  in  the  heart 
than  in  the  other  muscle,  and  if  the  resistance  to  be  overcome  is 
less  for  the  heart,  then  with  the  same  degree  of  irritability  in 
both  parts,  and  even  with  less  irritability  in  the  heart  than  in  the 
other  muscle,  we  wiM  see  a  movement  in  the  heart,  and  not  in 
that  other  muscle.  Now  a  simple  examination  of  the  vessels  of 
the  heart,  proves  that  they  contain  more  blood,  and  consequently 
more  stimulus,  than  the  other  striated  muscles.  Besides,  as  the 
heart  is  not  inserted  into  heavy  bones  to  be  moved,  it  has  less  re- 
sistance to  overcome  when  it  has  not  to  circulate  the  blood,  as 
after  death,  or  when  it  is  out  of  the  chest,  than  the  muscles  of 
animal  life.  Some  muscles  in  the  face  and  the  diaphragm,  being 
almost  without  an  external  resistance,  when  their  contractions 
do  not  go  so  far,  it  results  that  they  are  moved  much  more  easily 
after  death,  than  the  muscles  of  the  limbs.  In  consequence  of 
these  views,  I  believe  that,  although  there  is  in  die  blood-vessels 


of  all  the  muscles  of  the  body  a  principle  which  is  an  exciting 
cause  of  contractions,  there  are  no  contractions  produced,  be- 
cause the  quantity  of  that  principle  is  not  sufficient,  or  because 
the  resistance  to  contractions  in  many  muscles  is  greater  than  in 
the  heart. 

I  must,  in  conclusion,  say,  that  I  do  not  advance  my  theory  of 
the  rhythmical  movements  as  perfectly  proved.  I  believe  it  is 
true,  and  that  there  are  a  great  many  facts  which  appear  posi- 
tively to  prove  it.  What  I  can  assert  is,  that  it  is  by  far  much 
more  in  harmony  with  all  the  known  facts,  than  the  other  theories. 


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